
data_Exp1_p1_MHI
_database_code_depnum_ccdc_archive 'CCDC 2521384'
loop_
_audit_author_name
_audit_author_address
'Katarzyna Skrzynska'
;ESRF
France
;
_audit_update_record             
;
2026-01-08 deposited with the CCDC.	2026-01-08 downloaded from the CCDC.
;
# start Validation Reply Form
_vrf_GEOM001_Exp1_p1_MHI         
;
PROBLEM: _geom_bond_atom_site_label_1 is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_GEOM002_Exp1_p1_MHI         
;
PROBLEM: _geom_bond_atom_site_label_2 is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_GEOM003_Exp1_p1_MHI         
;
PROBLEM: _geom_bond_distance is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_GEOM006_Exp1_p1_MHI         
;
PROBLEM: _geom_angle_atom_site_label_2 is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_GEOM007_Exp1_p1_MHI         
;
PROBLEM: _geom_angle_atom_site_label_3 is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_GEOM008_Exp1_p1_MHI         
;
PROBLEM: _geom_angle is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_PLAT049_Exp1_p1_MHI         
;
PROBLEM: Calculated Density Less Than 1.0 gcm-3 .........     0.8466 Check
RESPONSE: The structure consists of an open, porous water framework containing cages populated by methane molecules, resulting in a lower density compared to compact ice phases.
;
# Added during the CSD deposition process: Thursday 08 January 2026 04:02 PM
# end Validation Reply Form

_audit_creation_date             2026-01-07
_audit_creation_method           
;
Olex2 1.5
(compiled 2025.07.13 svn.rb7424aed for OlexSys, GUI svn.r7314)
;
_shelx_SHELXL_version_number     2019/3
_audit_contact_author_address    ?
_audit_contact_author_email      ?
_audit_contact_author_phone      ?
_publ_contact_author_id_orcid    ?
_publ_section_references         
;
Dolomanov, O.V., Bourhis, L.J., Gildea, R.J, Howard, J.A.K. & Puschmann, H.
 (2009), J. Appl. Cryst. 42, 339-341.

Sheldrick, G.M. (2015). Acta Cryst. C71, 3-8.
;
_chemical_name_common            ?
_chemical_name_systematic        ?
_chemical_formula_moiety         '46(O), 7.8(C)'
_chemical_formula_sum            'C7.80 O46'
_chemical_formula_weight         829.68
_chemical_melting_point          ?
_chemical_oxdiff_formula         'C H O '
loop_
_atom_type_symbol
_atom_type_description
_atom_type_scat_dispersion_real
_atom_type_scat_dispersion_imag
_atom_type_scat_source
C C 0.0033 0.0016 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
O O 0.0106 0.0060 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'

_shelx_space_group_comment       
;
The symmetry employed for this shelxl refinement is uniquely defined
by the following loop, which should always be used as a source of
symmetry information in preference to the above space-group names.
They are only intended as comments.
;
_space_group_crystal_system      cubic
_space_group_IT_number           223
_space_group_name_H-M_alt        'P m -3 n'
_space_group_name_Hall           '-P 4n 2 3'
loop_
_space_group_symop_operation_xyz
'x, y, z'
'-x, -y, z'
'-x, y, -z'
'x, -y, -z'
'z, x, y'
'z, -x, -y'
'-z, -x, y'
'-z, x, -y'
'y, z, x'
'-y, z, -x'
'y, -z, -x'
'-y, -z, x'
'y+1/2, x+1/2, -z+1/2'
'-y+1/2, -x+1/2, -z+1/2'
'y+1/2, -x+1/2, z+1/2'
'-y+1/2, x+1/2, z+1/2'
'x+1/2, z+1/2, -y+1/2'
'-x+1/2, z+1/2, y+1/2'
'-x+1/2, -z+1/2, -y+1/2'
'x+1/2, -z+1/2, y+1/2'
'z+1/2, y+1/2, -x+1/2'
'z+1/2, -y+1/2, x+1/2'
'-z+1/2, y+1/2, x+1/2'
'-z+1/2, -y+1/2, -x+1/2'
'-x, -y, -z'
'x, y, -z'
'x, -y, z'
'-x, y, z'
'-z, -x, -y'
'-z, x, y'
'z, x, -y'
'z, -x, y'
'-y, -z, -x'
'y, -z, x'
'-y, z, x'
'y, z, -x'
'-y-1/2, -x-1/2, z-1/2'
'y-1/2, x-1/2, z-1/2'
'-y-1/2, x-1/2, -z-1/2'
'y-1/2, -x-1/2, -z-1/2'
'-x-1/2, -z-1/2, y-1/2'
'x-1/2, -z-1/2, -y-1/2'
'x-1/2, z-1/2, y-1/2'
'-x-1/2, z-1/2, -y-1/2'
'-z-1/2, -y-1/2, x-1/2'
'-z-1/2, y-1/2, -x-1/2'
'z-1/2, -y-1/2, -x-1/2'
'z-1/2, y-1/2, x-1/2'

_cell_length_a                   11.7623(4)
_cell_length_b                   11.7623(4)
_cell_length_c                   11.7623(4)
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_volume                     1627.33(18)
_cell_formula_units_Z            1
_cell_measurement_reflns_used    581
_cell_measurement_temperature    296.15
_cell_measurement_pressure       520000(20000)
_cell_measurement_theta_max      19.9220
_cell_measurement_theta_min      1.8240
_shelx_estimated_absorpt_T_max   0.999
_shelx_estimated_absorpt_T_min   0.999
_exptl_absorpt_coefficient_mu    0.097
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.05624
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   
;
CrysAlisPro 1.171.43.125a (Rigaku Oxford Diffraction, 2024)
Empirical absorption correction using spherical harmonics,
implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_absorpt_special_details   ?
_exptl_crystal_colour            ?
_exptl_crystal_density_diffrn    0.847
_exptl_crystal_density_meas      ?
_exptl_crystal_density_method    ?
_exptl_crystal_description       irregular
_exptl_crystal_F_000             415
_exptl_crystal_size_max          0.01
_exptl_crystal_size_mid          0.01
_exptl_crystal_size_min          0.01
_exptl_transmission_factor_max   ?
_exptl_transmission_factor_min   ?
_diffrn_reflns_av_R_equivalents  0.0278
_diffrn_reflns_av_unetI/netI     0.0124
_diffrn_reflns_Laue_measured_fraction_full 0.986
_diffrn_reflns_Laue_measured_fraction_max 0.990
_diffrn_reflns_limit_h_max       15
_diffrn_reflns_limit_h_min       -14
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       -15
_diffrn_reflns_limit_l_max       6
_diffrn_reflns_limit_l_min       -9
_diffrn_reflns_number            2740
_diffrn_reflns_point_group_measured_fraction_full 0.986
_diffrn_reflns_point_group_measured_fraction_max 0.990
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         28.223
_diffrn_reflns_theta_min         4.244
_diffrn_ambient_temperature      296.15
_diffrn_detector                 'Hybrid Pixel Array Detector'
_diffrn_detector_area_resol_mean 13.3333
_diffrn_measured_fraction_theta_full 0.986
_diffrn_measured_fraction_theta_max 0.990
_diffrn_measurement_details      
;
List of Runs (angles in degrees, time in seconds):

  # Type    Start    End  Width  tₑₓₚ   ω     θ     κ     φ   Frames
#--------------------------------------------------------------------------
  1  ω    -32.00  29.50   0.50    3.00    --    0.00   0.00   0.00  123
;
_diffrn_measurement_device       'abstract diffractometer'
_diffrn_measurement_device_type  
'esperanto-CrysAlisPro-abstract goniometer imported esperanto images'
_diffrn_measurement_method       'ω scans'
_diffrn_orient_matrix_axis[1]    matrixX
_diffrn_orient_matrix_axis[2]    matrixY
_diffrn_orient_matrix_axis[3]    matrixZ
_diffrn_orient_matrix_type       
'CrysAlisPro convention (1999,Acta A55,543-557)'
_diffrn_orient_matrix_UB_11      0.0089789000
_diffrn_orient_matrix_UB_12      0.0051490000
_diffrn_orient_matrix_UB_13      -0.0299817000
_diffrn_orient_matrix_UB_21      -0.0063443000
_diffrn_orient_matrix_UB_22      0.0309837000
_diffrn_orient_matrix_UB_23      0.0034045000
_diffrn_orient_matrix_UB_31      0.0298519000
_diffrn_orient_matrix_UB_32      0.0050474000
_diffrn_orient_matrix_UB_33      0.0097645000
_diffrn_radiation_monochromator  synchrotron
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           synchrotron
_diffrn_radiation_wavelength     0.71075
_diffrn_source                   synchrotron
_reflns_Friedel_coverage         0.000
_reflns_Friedel_fraction_full    .
_reflns_Friedel_fraction_max     .
_reflns_number_gt                263
_reflns_number_total             387
_reflns_special_details          
;
 Reflections were merged by SHELXL according to the crystal
 class for the calculation of statistics and refinement.
 
 _reflns_Friedel_fraction is defined as the number of unique
 Friedel pairs measured divided by the number that would be
 possible theoretically, ignoring centric projections and
 systematic absences.
;
_reflns_threshold_expression     'I > 2σ(I)'
_computing_cell_refinement       'CrysAlisPro 1.171.43.125a (Rigaku OD, 2024)'
_computing_data_collection       
'CrysAlisPro 1.171.43.125a (Rigaku OD, 2024) (IMPORT)'
_computing_data_reduction        'CrysAlisPro 1.171.43.125a (Rigaku OD, 2024)'
_computing_molecular_graphics    'Olex2 1.5 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 1.5 (Dolomanov et al., 2009)'
_computing_structure_refinement  'SHELXL 2019/3 (Sheldrick, 2015)'
_computing_structure_solution    'SHELXT 2014/5 (Sheldrick, 2014)'
_refine_diff_density_max         0.538
_refine_diff_density_min         -0.170
_refine_diff_density_rms         0.098
_refine_ls_extinction_coef       .
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.283
_refine_ls_hydrogen_treatment    undef
_refine_ls_matrix_type           full
_refine_ls_number_parameters     15
_refine_ls_number_reflns         387
_refine_ls_number_restraints     0
_refine_ls_R_factor_all          0.1010
_refine_ls_R_factor_gt           0.0836
_refine_ls_restrained_S_all      1.283
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details     
'w=1/[σ²(Fo²)+(0.2000P)²] where P=(Fo²+2Fc²)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.2866
_refine_ls_wR_factor_ref         0.3245
_refine_special_details          ?
_olex2_refinement_description    
;
;
_atom_sites_solution_hydrogens   .
_atom_sites_solution_primary     ?
_atom_sites_solution_secondary   ?
loop_
_atom_site_label
_atom_site_type_symbol
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_U_iso_or_equiv
_atom_site_adp_type
_atom_site_occupancy
_atom_site_site_symmetry_order
_atom_site_calc_flag
_atom_site_refinement_flags_posn
_atom_site_refinement_flags_adp
_atom_site_refinement_flags_occupancy
_atom_site_disorder_assembly
_atom_site_disorder_group
O1 O 0.250000 0.000000 0.500000 0.0598(14) Uani 1 8 d S T P . .
O2 O 0.18344(13) 0.18344(13) 0.18344(13) 0.0618(12) Uani 1 3 d S T P . .
O3 O 0.000000 0.30834(19) 0.11641(16) 0.0632(12) Uani 1 2 d S T P . .
C2 C 0.000000 0.000000 0.000000 0.066(5) Uiso 0.90(4) 24 d S . . . .
C1 C 0.250000 0.500000 0.000000 0.149(4) Uiso 1 8 d S . P . .


_geom_special_details            
;
 All esds (except the esd in the dihedral angle between two l.s. planes)
 are estimated using the full covariance matrix.  The cell esds are taken
 into account individually in the estimation of esds in distances, angles
 and torsion angles; correlations between esds in cell parameters are only
 used when they are defined by crystal symmetry.  An approximate (isotropic)
 treatment of cell esds is used for estimating esds involving l.s. planes.
;
loop_
_axis.id
_axis.system
_axis.type
_axis.equipment
_axis.parity
_axis.depends_on
_axis.zero
_axis.vector[1]
_axis.vector[2]
_axis.vector[3]
source abstract . source . . . 0.99988797 0.00000000 -0.01496808
omega abstract rotation goniometer -1 . 0.74380000 0.00000000 0.00000000
1.00000000
kappa abstract rotation goniometer -1 omega 0.00084000 -0.76604444 0.00000000
0.64278761
phi abstract rotation goniometer -1 kappa . 0.00000000 0.00000000 1.00000000
theta abstract rotation goniometer -1 . -0.88015000 0.00000000 0.00000000
1.00000000
matrixX abstract general general . phi . 1.00000000 0.00000000 0.00000000
matrixY abstract general general . phi . 0.00000000 1.00000000 0.00000000
matrixZ abstract general general . phi . 0.00000000 0.00000000 1.00000000
dacX abstract translation general . phi . 0.00000000 1.00000000 0.00000000
dacY abstract translation general . phi . -1.00000000 0.00000000 0.00000000
dacZ abstract translation general . phi . 0.00000000 0.00000000 1.00000000

_olex2_submission_special_instructions 'No special instructions were received'
_oxdiff_exptl_absorpt_empirical_details 
;
Empirical correction (ABSPACK) includes:
- Absorption correction using spherical harmonics
- Frame scaling
;
_oxdiff_exptl_absorpt_empirical_full_max 6.167
_oxdiff_exptl_absorpt_empirical_full_min 0.357

data_Exp1_p2_MHI
_database_code_depnum_ccdc_archive 'CCDC 2521385'
loop_
_audit_author_name
_audit_author_address
'Katarzyna Skrzynska'
;ESRF
France
;
_audit_update_record             
;
2026-01-08 deposited with the CCDC.	2026-01-08 downloaded from the CCDC.
;
# start Validation Reply Form
_vrf_GEOM001_Exp1_p2_MHI         
;
PROBLEM: _geom_bond_atom_site_label_1 is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_GEOM002_Exp1_p2_MHI         
;
PROBLEM: _geom_bond_atom_site_label_2 is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_GEOM003_Exp1_p2_MHI         
;
PROBLEM: _geom_bond_distance is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_GEOM006_Exp1_p2_MHI         
;
PROBLEM: _geom_angle_atom_site_label_2 is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_GEOM007_Exp1_p2_MHI         
;
PROBLEM: _geom_angle_atom_site_label_3 is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_GEOM008_Exp1_p2_MHI         
;
PROBLEM: _geom_angle is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_PLAT049_Exp1_p2_MHI         
;
PROBLEM: Calculated Density Less Than 1.0 gcm-3 .........     0.8530 Check
RESPONSE: The structure consists of an open, porous water framework containing cages populated by methane molecules, resulting in a lower density compared to compact ice phases.
;
# Added during the CSD deposition process: Thursday 08 January 2026 05:21 PM
# end Validation Reply Form

_audit_creation_date             2025-05-19
_audit_creation_method           
;
Olex2 1.5
(compiled 2025.04.05 svn.rf049d14d for OlexSys, GUI svn.r7224)
;
_shelx_SHELXL_version_number     2019/3
_audit_contact_author_address    ?
_audit_contact_author_email      ?
_audit_contact_author_phone      ?
_publ_contact_author_id_orcid    ?
_publ_section_references         
;
Dolomanov, O.V., Bourhis, L.J., Gildea, R.J, Howard, J.A.K. & Puschmann, H.
 (2009), J. Appl. Cryst. 42, 339-341.

Sheldrick, G.M. (2015). Acta Cryst. C71, 3-8.
;
_chemical_name_common            ?
_chemical_name_systematic        'methane clathrate hydrate'
_chemical_formula_moiety         '46(O), 7.802(C)'
_chemical_formula_sum            'C7.80 O46'
_chemical_formula_weight         829.68
_chemical_melting_point          ?
_chemical_oxdiff_formula         'C H O'
loop_
_atom_type_symbol
_atom_type_description
_atom_type_scat_dispersion_real
_atom_type_scat_dispersion_imag
_atom_type_scat_source
C C 0.0033 0.0016 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
O O 0.0106 0.0060 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'

_shelx_space_group_comment       
;
The symmetry employed for this shelxl refinement is uniquely defined
by the following loop, which should always be used as a source of
symmetry information in preference to the above space-group names.
They are only intended as comments.
;
_space_group_crystal_system      cubic
_space_group_IT_number           223
_space_group_name_H-M_alt        'P m -3 n'
_space_group_name_Hall           '-P 4n 2 3'
loop_
_space_group_symop_operation_xyz
'x, y, z'
'-x, -y, z'
'-x, y, -z'
'x, -y, -z'
'z, x, y'
'z, -x, -y'
'-z, -x, y'
'-z, x, -y'
'y, z, x'
'-y, z, -x'
'y, -z, -x'
'-y, -z, x'
'y+1/2, x+1/2, -z+1/2'
'-y+1/2, -x+1/2, -z+1/2'
'y+1/2, -x+1/2, z+1/2'
'-y+1/2, x+1/2, z+1/2'
'x+1/2, z+1/2, -y+1/2'
'-x+1/2, z+1/2, y+1/2'
'-x+1/2, -z+1/2, -y+1/2'
'x+1/2, -z+1/2, y+1/2'
'z+1/2, y+1/2, -x+1/2'
'z+1/2, -y+1/2, x+1/2'
'-z+1/2, y+1/2, x+1/2'
'-z+1/2, -y+1/2, -x+1/2'
'-x, -y, -z'
'x, y, -z'
'x, -y, z'
'-x, y, z'
'-z, -x, -y'
'-z, x, y'
'z, x, -y'
'z, -x, y'
'-y, -z, -x'
'y, -z, x'
'-y, z, x'
'y, z, -x'
'-y-1/2, -x-1/2, z-1/2'
'y-1/2, x-1/2, z-1/2'
'-y-1/2, x-1/2, -z-1/2'
'y-1/2, -x-1/2, -z-1/2'
'-x-1/2, -z-1/2, y-1/2'
'x-1/2, -z-1/2, -y-1/2'
'x-1/2, z-1/2, y-1/2'
'-x-1/2, z-1/2, -y-1/2'
'-z-1/2, -y-1/2, x-1/2'
'-z-1/2, y-1/2, -x-1/2'
'z-1/2, -y-1/2, -x-1/2'
'z-1/2, y-1/2, x-1/2'

_cell_length_a                   11.7331(4)
_cell_length_b                   11.7331(4)
_cell_length_c                   11.7331(4)
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_volume                     1615.25(18)
_cell_formula_units_Z            1
_cell_measurement_reflns_used    365
_cell_measurement_temperature    296.15
_cell_measurement_pressure       620000(20000)
_cell_measurement_theta_max      20.1740
_cell_measurement_theta_min      1.8290
_shelx_estimated_absorpt_T_max   0.990
_shelx_estimated_absorpt_T_min   0.990
_exptl_absorpt_coefficient_mu    0.098
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.06539
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   
;
CrysAlisPro 1.171.43.95a (Rigaku Oxford Diffraction, 2023)
Empirical absorption correction using spherical harmonics,
implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_absorpt_special_details   ?
_exptl_crystal_colour            ?
_exptl_crystal_density_diffrn    0.853
_exptl_crystal_density_meas      ?
_exptl_crystal_density_method    ?
_exptl_crystal_description       irregular
_exptl_crystal_F_000             415
_exptl_crystal_size_max          0.01
_exptl_crystal_size_mid          0.01
_exptl_crystal_size_min          0.01
_exptl_transmission_factor_max   ?
_exptl_transmission_factor_min   ?
_diffrn_reflns_av_R_equivalents  0.0431
_diffrn_reflns_av_unetI/netI     0.0158
_diffrn_reflns_Laue_measured_fraction_full 0.986
_diffrn_reflns_Laue_measured_fraction_max 0.990
_diffrn_reflns_limit_h_max       15
_diffrn_reflns_limit_h_min       -15
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       -14
_diffrn_reflns_limit_l_max       9
_diffrn_reflns_limit_l_min       -6
_diffrn_reflns_number            2751
_diffrn_reflns_point_group_measured_fraction_full 0.986
_diffrn_reflns_point_group_measured_fraction_max 0.990
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         28.237
_diffrn_reflns_theta_min         4.255
_diffrn_ambient_temperature      296.15
_diffrn_detector                 'Hybrid Pixel Array Detector'
_diffrn_detector_area_resol_mean 13.3333
_diffrn_measured_fraction_theta_full 0.986
_diffrn_measured_fraction_theta_max 0.990
_diffrn_measurement_details      
;
List of Runs (angles in degrees, time in seconds):

  # Type    Start    End  Width  tₑₓₚ   ω     θ     κ     φ   Frames
#--------------------------------------------------------------------------
  1  ω    -32.00  32.00   0.50    2.00    --    0.00   0.00   0.00  128
;
_diffrn_measurement_device       'abstract diffractometer'
_diffrn_measurement_device_type  
'esperanto-CrysAlisPro-abstract goniometer imported esperanto images'
_diffrn_measurement_method       'ω scans'
_diffrn_orient_matrix_axis[1]    matrixX
_diffrn_orient_matrix_axis[2]    matrixY
_diffrn_orient_matrix_axis[3]    matrixZ
_diffrn_orient_matrix_type       
'CrysAlisPro convention (1999,Acta A55,543-557)'
_diffrn_orient_matrix_UB_11      0.0049706000
_diffrn_orient_matrix_UB_12      0.0097709000
_diffrn_orient_matrix_UB_13      0.0298399000
_diffrn_orient_matrix_UB_21      0.0310630000
_diffrn_orient_matrix_UB_22      -0.0065637000
_diffrn_orient_matrix_UB_23      -0.0030359000
_diffrn_orient_matrix_UB_31      0.0052087000
_diffrn_orient_matrix_UB_32      0.0296194000
_diffrn_orient_matrix_UB_33      -0.0106148000
_diffrn_radiation_monochromator  synchrotron
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           synchrotron
_diffrn_radiation_wavelength     0.71075
_diffrn_source                   synchrotron
_reflns_Friedel_coverage         0.000
_reflns_Friedel_fraction_full    .
_reflns_Friedel_fraction_max     .
_reflns_number_gt                236
_reflns_number_total             383
_reflns_special_details          
;
 Reflections were merged by SHELXL according to the crystal
 class for the calculation of statistics and refinement.
 
 _reflns_Friedel_fraction is defined as the number of unique
 Friedel pairs measured divided by the number that would be
 possible theoretically, ignoring centric projections and
 systematic absences.
;
_reflns_threshold_expression     'I > 2σ(I)'
_computing_cell_refinement       'CrysAlisPro 1.171.43.95a (Rigaku OD, 2023)'
_computing_data_collection       
'CrysAlisPro 1.171.43.95a (Rigaku OD, 2023) (IMPORT)'
_computing_data_reduction        'CrysAlisPro 1.171.43.95a (Rigaku OD, 2023)'
_computing_molecular_graphics    'Olex2 1.5 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 1.5 (Dolomanov et al., 2009)'
_computing_structure_refinement  'SHELXL 2019/3 (Sheldrick, 2015)'
_computing_structure_solution    'SHELXT 2018/2 (Sheldrick, 2018)'
_refine_diff_density_max         0.420
_refine_diff_density_min         -0.156
_refine_diff_density_rms         0.084
_refine_ls_extinction_coef       .
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.060
_refine_ls_hydrogen_treatment    undef
_refine_ls_matrix_type           full
_refine_ls_number_parameters     15
_refine_ls_number_reflns         383
_refine_ls_number_restraints     0
_refine_ls_R_factor_all          0.1027
_refine_ls_R_factor_gt           0.0771
_refine_ls_restrained_S_all      1.060
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details     
'w=1/[σ²(Fo²)+(0.1564P)²+0.2810P] where P=(Fo²+2Fc²)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.2280
_refine_ls_wR_factor_ref         0.2647
_refine_special_details          ?
_olex2_refinement_description    
;
;
_atom_sites_solution_hydrogens   .
_atom_sites_solution_primary     ?
_atom_sites_solution_secondary   ?
loop_
_atom_site_label
_atom_site_type_symbol
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_U_iso_or_equiv
_atom_site_adp_type
_atom_site_occupancy
_atom_site_site_symmetry_order
_atom_site_calc_flag
_atom_site_refinement_flags_posn
_atom_site_refinement_flags_adp
_atom_site_refinement_flags_occupancy
_atom_site_disorder_assembly
_atom_site_disorder_group
O1 O 0.250000 0.000000 0.500000 0.0677(13) Uani 1 8 d S T P . .
O2 O 0.18351(12) 0.18351(12) 0.18351(12) 0.0683(11) Uani 1 3 d S T P . .
O3 O 0.000000 0.30869(19) 0.11675(17) 0.0696(10) Uani 1 2 d S T P . .
C2 C 0.000000 0.000000 0.000000 0.072(5) Uiso 0.90(3) 24 d S . . . .
C1 C 0.250000 0.500000 0.000000 0.154(4) Uiso 1 8 d S . P . .


_geom_special_details            
;
 All esds (except the esd in the dihedral angle between two l.s. planes)
 are estimated using the full covariance matrix.  The cell esds are taken
 into account individually in the estimation of esds in distances, angles
 and torsion angles; correlations between esds in cell parameters are only
 used when they are defined by crystal symmetry.  An approximate (isotropic)
 treatment of cell esds is used for estimating esds involving l.s. planes.
;
loop_
_axis.id
_axis.system
_axis.type
_axis.equipment
_axis.parity
_axis.depends_on
_axis.zero
_axis.vector[1]
_axis.vector[2]
_axis.vector[3]
source abstract . source . . . 0.99988797 0.00000000 -0.01496808
omega abstract rotation goniometer -1 . 0.74380000 0.00000000 0.00000000
1.00000000
kappa abstract rotation goniometer -1 omega 0.00084000 -0.76604444 0.00000000
0.64278761
phi abstract rotation goniometer -1 kappa . 0.00000000 0.00000000 1.00000000
theta abstract rotation goniometer -1 . -0.88015000 0.00000000 0.00000000
1.00000000
matrixX abstract general general . phi . 1.00000000 0.00000000 0.00000000
matrixY abstract general general . phi . 0.00000000 1.00000000 0.00000000
matrixZ abstract general general . phi . 0.00000000 0.00000000 1.00000000
dacX abstract translation general . phi . 0.00000000 1.00000000 0.00000000
dacY abstract translation general . phi . -1.00000000 0.00000000 0.00000000
dacZ abstract translation general . phi . 0.00000000 0.00000000 1.00000000

_olex2_submission_special_instructions 'No special instructions were received'
_oxdiff_exptl_absorpt_empirical_details 
;
Empirical correction (ABSPACK) includes:
- Absorption correction using spherical harmonics
- Frame scaling
;
_oxdiff_exptl_absorpt_empirical_full_max 3.204
_oxdiff_exptl_absorpt_empirical_full_min 0.178

data_Exp1_p3_MHI
_database_code_depnum_ccdc_archive 'CCDC 2521386'
loop_
_audit_author_name
_audit_author_address
'Katarzyna Skrzynska'
;ESRF
France
;
_audit_update_record             
;
2026-01-08 deposited with the CCDC.	2026-01-08 downloaded from the CCDC.
;
# start Validation Reply Form
_vrf_GEOM001_Exp1_p3_MHI         
;
PROBLEM: _geom_bond_atom_site_label_1 is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_GEOM002_Exp1_p3_MHI         
;
PROBLEM: _geom_bond_atom_site_label_2 is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_GEOM003_Exp1_p3_MHI         
;
PROBLEM: _geom_bond_distance is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_GEOM006_Exp1_p3_MHI         
;
PROBLEM: _geom_angle_atom_site_label_2 is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_GEOM007_Exp1_p3_MHI         
;
PROBLEM: _geom_angle_atom_site_label_3 is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_GEOM008_Exp1_p3_MHI         
;
PROBLEM: _geom_angle is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_PLAT049_Exp1_p3_MHI         
;
PROBLEM: Calculated Density Less Than 1.0 gcm-3 .........     0.8635 Check
RESPONSE: The structure consists of an open, porous water framework containing cages populated by methane molecules, resulting in a lower density compared to compact ice phases.
;
# Added during the CSD deposition process: Thursday 08 January 2026 05:26 PM
# end Validation Reply Form

_audit_creation_date             2025-05-19
_audit_creation_method           
;
Olex2 1.5
(compiled 2025.04.05 svn.rf049d14d for OlexSys, GUI svn.r7224)
;
_shelx_SHELXL_version_number     2019/3
_audit_contact_author_address    ?
_audit_contact_author_email      ?
_audit_contact_author_phone      ?
_publ_contact_author_id_orcid    ?
_publ_section_references         
;
Dolomanov, O.V., Bourhis, L.J., Gildea, R.J, Howard, J.A.K. & Puschmann, H.
 (2009), J. Appl. Cryst. 42, 339-341.

Sheldrick, G.M. (2015). Acta Cryst. C71, 3-8.
;
_chemical_name_common            ?
_chemical_name_systematic        'methane clathrate hydrate'
_chemical_formula_moiety         '46(O), 7.835(C)'
_chemical_formula_sum            'C7.83 O46'
_chemical_formula_weight         830.04
_chemical_melting_point          ?
_chemical_oxdiff_formula         'C H O'
loop_
_atom_type_symbol
_atom_type_description
_atom_type_scat_dispersion_real
_atom_type_scat_dispersion_imag
_atom_type_scat_source
C C 0.0033 0.0016 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
O O 0.0106 0.0060 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'

_shelx_space_group_comment       
;
The symmetry employed for this shelxl refinement is uniquely defined
by the following loop, which should always be used as a source of
symmetry information in preference to the above space-group names.
They are only intended as comments.
;
_space_group_crystal_system      cubic
_space_group_IT_number           223
_space_group_name_H-M_alt        'P m -3 n'
_space_group_name_Hall           '-P 4n 2 3'
loop_
_space_group_symop_operation_xyz
'x, y, z'
'-x, -y, z'
'-x, y, -z'
'x, -y, -z'
'z, x, y'
'z, -x, -y'
'-z, -x, y'
'-z, x, -y'
'y, z, x'
'-y, z, -x'
'y, -z, -x'
'-y, -z, x'
'y+1/2, x+1/2, -z+1/2'
'-y+1/2, -x+1/2, -z+1/2'
'y+1/2, -x+1/2, z+1/2'
'-y+1/2, x+1/2, z+1/2'
'x+1/2, z+1/2, -y+1/2'
'-x+1/2, z+1/2, y+1/2'
'-x+1/2, -z+1/2, -y+1/2'
'x+1/2, -z+1/2, y+1/2'
'z+1/2, y+1/2, -x+1/2'
'z+1/2, -y+1/2, x+1/2'
'-z+1/2, y+1/2, x+1/2'
'-z+1/2, -y+1/2, -x+1/2'
'-x, -y, -z'
'x, y, -z'
'x, -y, z'
'-x, y, z'
'-z, -x, -y'
'-z, x, y'
'z, x, -y'
'z, -x, y'
'-y, -z, -x'
'y, -z, x'
'-y, z, x'
'y, z, -x'
'-y-1/2, -x-1/2, z-1/2'
'y-1/2, x-1/2, z-1/2'
'-y-1/2, x-1/2, -z-1/2'
'y-1/2, -x-1/2, -z-1/2'
'-x-1/2, -z-1/2, y-1/2'
'x-1/2, -z-1/2, -y-1/2'
'x-1/2, z-1/2, y-1/2'
'-x-1/2, z-1/2, -y-1/2'
'-z-1/2, -y-1/2, x-1/2'
'-z-1/2, y-1/2, -x-1/2'
'z-1/2, -y-1/2, -x-1/2'
'z-1/2, y-1/2, x-1/2'

_cell_length_a                   11.6876(5)
_cell_length_b                   11.6876(5)
_cell_length_c                   11.6876(5)
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_volume                     1596.5(2)
_cell_formula_units_Z            1
_cell_measurement_reflns_used    366
_cell_measurement_temperature    296.15
_cell_measurement_pressure       720000(20000)
_cell_measurement_theta_max      19.6460
_cell_measurement_theta_min      1.8340
_shelx_estimated_absorpt_T_max   0.990
_shelx_estimated_absorpt_T_min   0.990
_exptl_absorpt_coefficient_mu    0.099
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.24195
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   
;
CrysAlisPro 1.171.43.95a (Rigaku Oxford Diffraction, 2023)
Empirical absorption correction using spherical harmonics,
implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_absorpt_special_details   ?
_exptl_crystal_colour            ?
_exptl_crystal_density_diffrn    0.863
_exptl_crystal_density_meas      ?
_exptl_crystal_density_method    ?
_exptl_crystal_description       irregular
_exptl_crystal_F_000             415
_exptl_crystal_size_max          0.01
_exptl_crystal_size_mid          0.01
_exptl_crystal_size_min          0.01
_exptl_transmission_factor_max   ?
_exptl_transmission_factor_min   ?
_diffrn_reflns_av_R_equivalents  0.0324
_diffrn_reflns_av_unetI/netI     0.0172
_diffrn_reflns_Laue_measured_fraction_full 0.982
_diffrn_reflns_Laue_measured_fraction_max 0.984
_diffrn_reflns_limit_h_max       14
_diffrn_reflns_limit_h_min       -15
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       -15
_diffrn_reflns_limit_l_max       6
_diffrn_reflns_limit_l_min       -8
_diffrn_reflns_number            2746
_diffrn_reflns_point_group_measured_fraction_full 0.982
_diffrn_reflns_point_group_measured_fraction_max 0.984
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         28.230
_diffrn_reflns_theta_min         4.271
_diffrn_ambient_temperature      296.15
_diffrn_detector                 'Hybrid Pixel Array Detector'
_diffrn_detector_area_resol_mean 13.3333
_diffrn_measured_fraction_theta_full 0.982
_diffrn_measured_fraction_theta_max 0.984
_diffrn_measurement_details      
;
List of Runs (angles in degrees, time in seconds):

  # Type    Start    End  Width  tₑₓₚ   ω     θ     κ     φ   Frames
#--------------------------------------------------------------------------
  1  ω    -32.00  30.00   0.50    1.00    --    0.00   0.00   0.00  124
;
_diffrn_measurement_device       'abstract diffractometer'
_diffrn_measurement_device_type  
'esperanto-CrysAlisPro-abstract goniometer imported esperanto images'
_diffrn_measurement_method       'ω scans'
_diffrn_orient_matrix_axis[1]    matrixX
_diffrn_orient_matrix_axis[2]    matrixY
_diffrn_orient_matrix_axis[3]    matrixZ
_diffrn_orient_matrix_type       
'CrysAlisPro convention (1999,Acta A55,543-557)'
_diffrn_orient_matrix_UB_11      -0.0089986000
_diffrn_orient_matrix_UB_12      -0.0052553000
_diffrn_orient_matrix_UB_13      -0.0302220000
_diffrn_orient_matrix_UB_21      0.0064551000
_diffrn_orient_matrix_UB_22      -0.0311403000
_diffrn_orient_matrix_UB_23      0.0034940000
_diffrn_orient_matrix_UB_31      -0.0300346000
_diffrn_orient_matrix_UB_32      -0.0051242000
_diffrn_orient_matrix_UB_33      0.0097352000
_diffrn_radiation_monochromator  synchrotron
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           synchrotron
_diffrn_radiation_wavelength     0.71075
_diffrn_source                   synchrotron
_reflns_Friedel_coverage         0.000
_reflns_Friedel_fraction_full    .
_reflns_Friedel_fraction_max     .
_reflns_number_gt                251
_reflns_number_total             378
_reflns_special_details          
;
 Reflections were merged by SHELXL according to the crystal
 class for the calculation of statistics and refinement.
 
 _reflns_Friedel_fraction is defined as the number of unique
 Friedel pairs measured divided by the number that would be
 possible theoretically, ignoring centric projections and
 systematic absences.
;
_reflns_threshold_expression     'I > 2σ(I)'
_computing_cell_refinement       'CrysAlisPro 1.171.43.95a (Rigaku OD, 2023)'
_computing_data_collection       
'CrysAlisPro 1.171.43.95a (Rigaku OD, 2023) (IMPORT)'
_computing_data_reduction        'CrysAlisPro 1.171.43.95a (Rigaku OD, 2023)'
_computing_molecular_graphics    'Olex2 1.5 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 1.5 (Dolomanov et al., 2009)'
_computing_structure_refinement  'SHELXL 2019/3 (Sheldrick, 2015)'
_computing_structure_solution    'SHELXT 2018/2 (Sheldrick, 2018)'
_refine_diff_density_max         0.342
_refine_diff_density_min         -0.142
_refine_diff_density_rms         0.070
_refine_ls_extinction_coef       .
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.050
_refine_ls_hydrogen_treatment    undef
_refine_ls_matrix_type           full
_refine_ls_number_parameters     15
_refine_ls_number_reflns         378
_refine_ls_number_restraints     0
_refine_ls_R_factor_all          0.0914
_refine_ls_R_factor_gt           0.0703
_refine_ls_restrained_S_all      1.050
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details     
'w=1/[σ²(Fo²)+(0.1315P)²+0.4158P] where P=(Fo²+2Fc²)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.2088
_refine_ls_wR_factor_ref         0.2364
_refine_special_details          ?
_olex2_refinement_description    
;
;
_atom_sites_solution_hydrogens   .
_atom_sites_solution_primary     ?
_atom_sites_solution_secondary   ?
loop_
_atom_site_label
_atom_site_type_symbol
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_U_iso_or_equiv
_atom_site_adp_type
_atom_site_occupancy
_atom_site_site_symmetry_order
_atom_site_calc_flag
_atom_site_refinement_flags_posn
_atom_site_refinement_flags_adp
_atom_site_refinement_flags_occupancy
_atom_site_disorder_assembly
_atom_site_disorder_group
O1 O 0.250000 0.000000 0.500000 0.0656(12) Uani 1 8 d S T P . .
O2 O 0.18357(12) 0.18357(12) 0.18357(12) 0.0665(10) Uani 1 3 d S T P . .
O3 O 0.000000 0.30882(18) 0.11662(17) 0.0670(9) Uani 1 2 d S T P . .
C2 C 0.000000 0.000000 0.000000 0.068(4) Uiso 0.92(3) 24 d S . . . .
C1 C 0.250000 0.500000 0.000000 0.150(4) Uiso 1 8 d S . P . .


_geom_special_details            
;
 All esds (except the esd in the dihedral angle between two l.s. planes)
 are estimated using the full covariance matrix.  The cell esds are taken
 into account individually in the estimation of esds in distances, angles
 and torsion angles; correlations between esds in cell parameters are only
 used when they are defined by crystal symmetry.  An approximate (isotropic)
 treatment of cell esds is used for estimating esds involving l.s. planes.
;
loop_
_axis.id
_axis.system
_axis.type
_axis.equipment
_axis.parity
_axis.depends_on
_axis.zero
_axis.vector[1]
_axis.vector[2]
_axis.vector[3]
source abstract . source . . . 0.99988797 0.00000000 -0.01496808
omega abstract rotation goniometer -1 . 0.74380000 0.00000000 0.00000000
1.00000000
kappa abstract rotation goniometer -1 omega 0.00084000 -0.76604444 0.00000000
0.64278761
phi abstract rotation goniometer -1 kappa . 0.00000000 0.00000000 1.00000000
theta abstract rotation goniometer -1 . -0.88015000 0.00000000 0.00000000
1.00000000
matrixX abstract general general . phi . 1.00000000 0.00000000 0.00000000
matrixY abstract general general . phi . 0.00000000 1.00000000 0.00000000
matrixZ abstract general general . phi . 0.00000000 0.00000000 1.00000000
dacX abstract translation general . phi . 0.00000000 1.00000000 0.00000000
dacY abstract translation general . phi . -1.00000000 0.00000000 0.00000000
dacZ abstract translation general . phi . 0.00000000 0.00000000 1.00000000

_olex2_submission_special_instructions 'No special instructions were received'
_oxdiff_exptl_absorpt_empirical_details 
;
Empirical correction (ABSPACK) includes:
- Absorption correction using spherical harmonics
- Frame scaling
;
_oxdiff_exptl_absorpt_empirical_full_max 2.579
_oxdiff_exptl_absorpt_empirical_full_min 0.615

data_Exp1_p4_MHI
_database_code_depnum_ccdc_archive 'CCDC 2521387'
loop_
_audit_author_name
_audit_author_address
'Katarzyna Skrzynska'
;ESRF
France
;
_audit_update_record             
;
2026-01-08 deposited with the CCDC.	2026-01-08 downloaded from the CCDC.
;
# start Validation Reply Form
_vrf_GEOM001_Exp1_p4_MHI         
;
PROBLEM: _geom_bond_atom_site_label_1 is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_GEOM002_Exp1_p4_MHI         
;
PROBLEM: _geom_bond_atom_site_label_2 is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_GEOM003_Exp1_p4_MHI         
;
PROBLEM: _geom_bond_distance is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_GEOM006_Exp1_p4_MHI         
;
PROBLEM: _geom_angle_atom_site_label_2 is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_GEOM007_Exp1_p4_MHI         
;
PROBLEM: _geom_angle_atom_site_label_3 is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_GEOM008_Exp1_p4_MHI         
;
PROBLEM: _geom_angle is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_PLAT049_Exp1_p4_MHI         
;
PROBLEM: Calculated Density Less Than 1.0 gcm-3 .........     0.8715 Check
RESPONSE: The structure consists of an open, porous water framework containing cages populated by methane molecules, resulting in a lower density compared to compact ice phases.
;
# Added during the CSD deposition process: Thursday 08 January 2026 05:29 PM
# end Validation Reply Form

_audit_creation_date             2025-05-19
_audit_creation_method           
;
Olex2 1.5
(compiled 2025.04.05 svn.rf049d14d for OlexSys, GUI svn.r7224)
;
_shelx_SHELXL_version_number     2019/3
_audit_contact_author_address    ?
_audit_contact_author_email      ?
_audit_contact_author_phone      ?
_publ_contact_author_id_orcid    ?
_publ_section_references         
;
Dolomanov, O.V., Bourhis, L.J., Gildea, R.J, Howard, J.A.K. & Puschmann, H.
 (2009), J. Appl. Cryst. 42, 339-341.

Sheldrick, G.M. (2015). Acta Cryst. C71, 3-8.
;
_chemical_name_common            ?
_chemical_name_systematic        'methane clathrate hydrate'
_chemical_formula_moiety         '46(O), 7.858(C)'
_chemical_formula_sum            'C7.86 O46'
_chemical_formula_weight         830.40
_chemical_melting_point          ?
_chemical_oxdiff_formula         'C H O'
loop_
_atom_type_symbol
_atom_type_description
_atom_type_scat_dispersion_real
_atom_type_scat_dispersion_imag
_atom_type_scat_source
C C 0.0033 0.0016 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
O O 0.0106 0.0060 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'

_shelx_space_group_comment       
;
The symmetry employed for this shelxl refinement is uniquely defined
by the following loop, which should always be used as a source of
symmetry information in preference to the above space-group names.
They are only intended as comments.
;
_space_group_crystal_system      cubic
_space_group_IT_number           223
_space_group_name_H-M_alt        'P m -3 n'
_space_group_name_Hall           '-P 4n 2 3'
loop_
_space_group_symop_operation_xyz
'x, y, z'
'-x, -y, z'
'-x, y, -z'
'x, -y, -z'
'z, x, y'
'z, -x, -y'
'-z, -x, y'
'-z, x, -y'
'y, z, x'
'-y, z, -x'
'y, -z, -x'
'-y, -z, x'
'y+1/2, x+1/2, -z+1/2'
'-y+1/2, -x+1/2, -z+1/2'
'y+1/2, -x+1/2, z+1/2'
'-y+1/2, x+1/2, z+1/2'
'x+1/2, z+1/2, -y+1/2'
'-x+1/2, z+1/2, y+1/2'
'-x+1/2, -z+1/2, -y+1/2'
'x+1/2, -z+1/2, y+1/2'
'z+1/2, y+1/2, -x+1/2'
'z+1/2, -y+1/2, x+1/2'
'-z+1/2, y+1/2, x+1/2'
'-z+1/2, -y+1/2, -x+1/2'
'-x, -y, -z'
'x, y, -z'
'x, -y, z'
'-x, y, z'
'-z, -x, -y'
'-z, x, y'
'z, x, -y'
'z, -x, y'
'-y, -z, -x'
'y, -z, x'
'-y, z, x'
'y, z, -x'
'-y-1/2, -x-1/2, z-1/2'
'y-1/2, x-1/2, z-1/2'
'-y-1/2, x-1/2, -z-1/2'
'y-1/2, -x-1/2, -z-1/2'
'-x-1/2, -z-1/2, y-1/2'
'x-1/2, -z-1/2, -y-1/2'
'x-1/2, z-1/2, y-1/2'
'-x-1/2, z-1/2, -y-1/2'
'-z-1/2, -y-1/2, x-1/2'
'-z-1/2, y-1/2, -x-1/2'
'z-1/2, -y-1/2, -x-1/2'
'z-1/2, y-1/2, x-1/2'

_cell_length_a                   11.6526(5)
_cell_length_b                   11.6526(5)
_cell_length_c                   11.6526(5)
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_volume                     1582.2(2)
_cell_formula_units_Z            1
_cell_measurement_reflns_used    367
_cell_measurement_temperature    296.15
_cell_measurement_pressure       830000(20000)
_cell_measurement_theta_max      19.5900
_cell_measurement_theta_min      1.8370
_shelx_estimated_absorpt_T_max   0.990
_shelx_estimated_absorpt_T_min   0.990
_exptl_absorpt_coefficient_mu    0.100
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.18598
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   
;
CrysAlisPro 1.171.43.95a (Rigaku Oxford Diffraction, 2023)
Empirical absorption correction using spherical harmonics,
implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_absorpt_special_details   ?
_exptl_crystal_colour            ?
_exptl_crystal_density_diffrn    0.872
_exptl_crystal_density_meas      ?
_exptl_crystal_density_method    ?
_exptl_crystal_description       irregular
_exptl_crystal_F_000             415
_exptl_crystal_size_max          0.01
_exptl_crystal_size_mid          0.01
_exptl_crystal_size_min          0.01
_exptl_transmission_factor_max   ?
_exptl_transmission_factor_min   ?
_diffrn_reflns_av_R_equivalents  0.0287
_diffrn_reflns_av_unetI/netI     0.0141
_diffrn_reflns_Laue_measured_fraction_full 0.982
_diffrn_reflns_Laue_measured_fraction_max 0.984
_diffrn_reflns_limit_h_max       14
_diffrn_reflns_limit_h_min       -15
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       -15
_diffrn_reflns_limit_l_max       6
_diffrn_reflns_limit_l_min       -8
_diffrn_reflns_number            2704
_diffrn_reflns_point_group_measured_fraction_full 0.982
_diffrn_reflns_point_group_measured_fraction_max 0.984
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         28.258
_diffrn_reflns_theta_min         4.284
_diffrn_ambient_temperature      296.15
_diffrn_detector                 'Hybrid Pixel Array Detector'
_diffrn_detector_area_resol_mean 13.3333
_diffrn_measured_fraction_theta_full 0.982
_diffrn_measured_fraction_theta_max 0.984
_diffrn_measurement_details      
;
List of Runs (angles in degrees, time in seconds):

  # Type    Start    End  Width  tₑₓₚ   ω     θ     κ     φ   Frames
#--------------------------------------------------------------------------
  1  ω    -32.00  30.00   0.50    1.00    --    0.00   0.00   0.00  124
;
_diffrn_measurement_device       'abstract diffractometer'
_diffrn_measurement_device_type  
'esperanto-CrysAlisPro-abstract goniometer imported esperanto images'
_diffrn_measurement_method       'ω scans'
_diffrn_orient_matrix_axis[1]    matrixX
_diffrn_orient_matrix_axis[2]    matrixY
_diffrn_orient_matrix_axis[3]    matrixZ
_diffrn_orient_matrix_type       
'CrysAlisPro convention (1999,Acta A55,543-557)'
_diffrn_orient_matrix_UB_11      -0.0090190000
_diffrn_orient_matrix_UB_12      -0.0053131000
_diffrn_orient_matrix_UB_13      -0.0303043000
_diffrn_orient_matrix_UB_21      0.0064914000
_diffrn_orient_matrix_UB_22      -0.0312257000
_diffrn_orient_matrix_UB_23      0.0035454000
_diffrn_orient_matrix_UB_31      -0.0301284000
_diffrn_orient_matrix_UB_32      -0.0051458000
_diffrn_orient_matrix_UB_33      0.0097616000
_diffrn_radiation_monochromator  synchrotron
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           synchrotron
_diffrn_radiation_wavelength     0.71075
_diffrn_source                   synchrotron
_reflns_Friedel_coverage         0.000
_reflns_Friedel_fraction_full    .
_reflns_Friedel_fraction_max     .
_reflns_number_gt                247
_reflns_number_total             374
_reflns_special_details          
;
 Reflections were merged by SHELXL according to the crystal
 class for the calculation of statistics and refinement.
 
 _reflns_Friedel_fraction is defined as the number of unique
 Friedel pairs measured divided by the number that would be
 possible theoretically, ignoring centric projections and
 systematic absences.
;
_reflns_threshold_expression     'I > 2σ(I)'
_computing_cell_refinement       'CrysAlisPro 1.171.43.95a (Rigaku OD, 2023)'
_computing_data_collection       
'CrysAlisPro 1.171.43.95a (Rigaku OD, 2023) (IMPORT)'
_computing_data_reduction        'CrysAlisPro 1.171.43.95a (Rigaku OD, 2023)'
_computing_molecular_graphics    'Olex2 1.5 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 1.5 (Dolomanov et al., 2009)'
_computing_structure_refinement  'SHELXL 2019/3 (Sheldrick, 2015)'
_computing_structure_solution    'SHELXT 2018/2 (Sheldrick, 2018)'
_refine_diff_density_max         0.358
_refine_diff_density_min         -0.163
_refine_diff_density_rms         0.073
_refine_ls_extinction_coef       .
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.102
_refine_ls_hydrogen_treatment    undef
_refine_ls_matrix_type           full
_refine_ls_number_parameters     15
_refine_ls_number_reflns         374
_refine_ls_number_restraints     0
_refine_ls_R_factor_all          0.0902
_refine_ls_R_factor_gt           0.0698
_refine_ls_restrained_S_all      1.102
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details     
'w=1/[σ²(Fo²)+(0.1333P)²+0.2974P] where P=(Fo²+2Fc²)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.2076
_refine_ls_wR_factor_ref         0.2391
_refine_special_details          ?
_olex2_refinement_description    
;
;
_atom_sites_solution_hydrogens   .
_atom_sites_solution_primary     ?
_atom_sites_solution_secondary   ?
loop_
_atom_site_label
_atom_site_type_symbol
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_U_iso_or_equiv
_atom_site_adp_type
_atom_site_occupancy
_atom_site_site_symmetry_order
_atom_site_calc_flag
_atom_site_refinement_flags_posn
_atom_site_refinement_flags_adp
_atom_site_refinement_flags_occupancy
_atom_site_disorder_assembly
_atom_site_disorder_group
O1 O 0.250000 0.000000 0.500000 0.0645(12) Uani 1 8 d S T P . .
O2 O 0.18351(12) 0.18351(12) 0.18351(12) 0.0651(10) Uani 1 3 d S T P . .
O3 O 0.000000 0.30888(18) 0.11656(17) 0.0660(9) Uani 1 2 d S T P . .
C2 C 0.000000 0.000000 0.000000 0.068(4) Uiso 0.93(3) 24 d S . . . .
C1 C 0.250000 0.500000 0.000000 0.140(4) Uiso 1 8 d S . P . .


_geom_special_details            
;
 All esds (except the esd in the dihedral angle between two l.s. planes)
 are estimated using the full covariance matrix.  The cell esds are taken
 into account individually in the estimation of esds in distances, angles
 and torsion angles; correlations between esds in cell parameters are only
 used when they are defined by crystal symmetry.  An approximate (isotropic)
 treatment of cell esds is used for estimating esds involving l.s. planes.
;
loop_
_axis.id
_axis.system
_axis.type
_axis.equipment
_axis.parity
_axis.depends_on
_axis.zero
_axis.vector[1]
_axis.vector[2]
_axis.vector[3]
source abstract . source . . . 0.99988797 0.00000000 -0.01496808
omega abstract rotation goniometer -1 . 0.74380000 0.00000000 0.00000000
1.00000000
kappa abstract rotation goniometer -1 omega 0.00084000 -0.76604444 0.00000000
0.64278761
phi abstract rotation goniometer -1 kappa . 0.00000000 0.00000000 1.00000000
theta abstract rotation goniometer -1 . -0.88015000 0.00000000 0.00000000
1.00000000
matrixX abstract general general . phi . 1.00000000 0.00000000 0.00000000
matrixY abstract general general . phi . 0.00000000 1.00000000 0.00000000
matrixZ abstract general general . phi . 0.00000000 0.00000000 1.00000000
dacX abstract translation general . phi . 0.00000000 1.00000000 0.00000000
dacY abstract translation general . phi . -1.00000000 0.00000000 0.00000000
dacZ abstract translation general . phi . 0.00000000 0.00000000 1.00000000

_olex2_submission_special_instructions 'No special instructions were received'
_oxdiff_exptl_absorpt_empirical_details 
;
Empirical correction (ABSPACK) includes:
- Absorption correction using spherical harmonics
- Frame scaling
;
_oxdiff_exptl_absorpt_empirical_full_max 3.353
_oxdiff_exptl_absorpt_empirical_full_min 0.532

data_Exp1_p5_MHI
_database_code_depnum_ccdc_archive 'CCDC 2521388'
loop_
_audit_author_name
_audit_author_address
'Katarzyna Skrzynska'
;ESRF
France
;
_audit_update_record             
;
2026-01-08 deposited with the CCDC.	2026-01-08 downloaded from the CCDC.
;
# start Validation Reply Form
_vrf_GEOM001_Exp1_p5_MHI         
;
PROBLEM: _geom_bond_atom_site_label_1 is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_GEOM002_Exp1_p5_MHI         
;
PROBLEM: _geom_bond_atom_site_label_2 is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_GEOM003_Exp1_p5_MHI         
;
PROBLEM: _geom_bond_distance is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_GEOM006_Exp1_p5_MHI         
;
PROBLEM: _geom_angle_atom_site_label_2 is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_GEOM007_Exp1_p5_MHI         
;
PROBLEM: _geom_angle_atom_site_label_3 is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_GEOM008_Exp1_p5_MHI         
;
PROBLEM: _geom_angle is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_PLAT049_Exp1_p5_MHI         
;
PROBLEM: Calculated Density Less Than 1.0 gcm-3 .........     0.8770 Check
RESPONSE: The structure consists of an open, porous water framework containing cages populated by methane molecules, resulting in a lower density compared to compact ice phases.
;
# Added during the CSD deposition process: Thursday 08 January 2026 05:32 PM
# end Validation Reply Form

_audit_creation_date             2026-01-07
_audit_creation_method           
;
Olex2 1.5
(compiled 2025.07.13 svn.rb7424aed for OlexSys, GUI svn.r7314)
;
_shelx_SHELXL_version_number     2019/3
_audit_contact_author_address    ?
_audit_contact_author_email      ?
_audit_contact_author_phone      ?
_publ_contact_author_id_orcid    ?
_publ_section_references         
;
Dolomanov, O.V., Bourhis, L.J., Gildea, R.J, Howard, J.A.K. & Puschmann, H.
 (2009), J. Appl. Cryst. 42, 339-341.

Sheldrick, G.M. (2015). Acta Cryst. C71, 3-8.
;
_chemical_name_common            ?
_chemical_name_systematic        'methane clathrate hydrate'
_chemical_formula_moiety         '46(O), 7.896(C)'
_chemical_formula_sum            'C7.89 O46'
_chemical_formula_weight         830.76
_chemical_melting_point          ?
_chemical_oxdiff_formula         'C H O'
loop_
_atom_type_symbol
_atom_type_description
_atom_type_scat_dispersion_real
_atom_type_scat_dispersion_imag
_atom_type_scat_source
C C 0.0033 0.0016 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
O O 0.0106 0.0060 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'

_shelx_space_group_comment       
;
The symmetry employed for this shelxl refinement is uniquely defined
by the following loop, which should always be used as a source of
symmetry information in preference to the above space-group names.
They are only intended as comments.
;
_space_group_crystal_system      cubic
_space_group_IT_number           223
_space_group_name_H-M_alt        'P m -3 n'
_space_group_name_Hall           '-P 4n 2 3'
loop_
_space_group_symop_operation_xyz
'x, y, z'
'-x, -y, z'
'-x, y, -z'
'x, -y, -z'
'z, x, y'
'z, -x, -y'
'-z, -x, y'
'-z, x, -y'
'y, z, x'
'-y, z, -x'
'y, -z, -x'
'-y, -z, x'
'y+1/2, x+1/2, -z+1/2'
'-y+1/2, -x+1/2, -z+1/2'
'y+1/2, -x+1/2, z+1/2'
'-y+1/2, x+1/2, z+1/2'
'x+1/2, z+1/2, -y+1/2'
'-x+1/2, z+1/2, y+1/2'
'-x+1/2, -z+1/2, -y+1/2'
'x+1/2, -z+1/2, y+1/2'
'z+1/2, y+1/2, -x+1/2'
'z+1/2, -y+1/2, x+1/2'
'-z+1/2, y+1/2, x+1/2'
'-z+1/2, -y+1/2, -x+1/2'
'-x, -y, -z'
'x, y, -z'
'x, -y, z'
'-x, y, z'
'-z, -x, -y'
'-z, x, y'
'z, x, -y'
'z, -x, y'
'-y, -z, -x'
'y, -z, x'
'-y, z, x'
'y, z, -x'
'-y-1/2, -x-1/2, z-1/2'
'y-1/2, x-1/2, z-1/2'
'-y-1/2, x-1/2, -z-1/2'
'y-1/2, -x-1/2, -z-1/2'
'-x-1/2, -z-1/2, y-1/2'
'x-1/2, -z-1/2, -y-1/2'
'x-1/2, z-1/2, y-1/2'
'-x-1/2, z-1/2, -y-1/2'
'-z-1/2, -y-1/2, x-1/2'
'-z-1/2, y-1/2, -x-1/2'
'z-1/2, -y-1/2, -x-1/2'
'z-1/2, y-1/2, x-1/2'

_cell_length_a                   11.6305(5)
_cell_length_b                   11.6305(5)
_cell_length_c                   11.6305(5)
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_volume                     1573.2(2)
_cell_formula_units_Z            1
_cell_measurement_reflns_used    421
_cell_measurement_temperature    296.15
_cell_measurement_pressure       910000(20000)
_cell_measurement_theta_max      19.9140
_cell_measurement_theta_min      1.8400
_shelx_estimated_absorpt_T_max   0.990
_shelx_estimated_absorpt_T_min   0.990
_exptl_absorpt_coefficient_mu    0.101
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.46493
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   
;
CrysAlisPro 1.171.43.70a (Rigaku Oxford Diffraction, 2023)
Empirical absorption correction using spherical harmonics,
implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_absorpt_special_details   ?
_exptl_crystal_colour            ?
_exptl_crystal_density_diffrn    0.877
_exptl_crystal_density_meas      ?
_exptl_crystal_density_method    ?
_exptl_crystal_description       irregular
_exptl_crystal_F_000             415
_exptl_crystal_preparation       ?
_exptl_crystal_size_max          0.01
_exptl_crystal_size_mid          0.01
_exptl_crystal_size_min          0.01
_exptl_transmission_factor_max   ?
_exptl_transmission_factor_min   ?
_diffrn_reflns_av_R_equivalents  0.0337
_diffrn_reflns_av_unetI/netI     0.0173
_diffrn_reflns_Laue_measured_fraction_full 0.982
_diffrn_reflns_Laue_measured_fraction_max 0.984
_diffrn_reflns_limit_h_max       14
_diffrn_reflns_limit_h_min       -15
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       -15
_diffrn_reflns_limit_l_max       6
_diffrn_reflns_limit_l_min       -8
_diffrn_reflns_number            2679
_diffrn_reflns_point_group_measured_fraction_full 0.982
_diffrn_reflns_point_group_measured_fraction_max 0.984
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         28.124
_diffrn_reflns_theta_min         4.292
_diffrn_ambient_temperature      296.15
_diffrn_detector                 'Hybrid Pixel Array Detector'
_diffrn_detector_area_resol_mean 13.3333
_diffrn_measured_fraction_theta_full 0.982
_diffrn_measured_fraction_theta_max 0.984
_diffrn_measurement_details      
;
List of Runs (angles in degrees, time in seconds):

  # Type    Start    End  Width  tₑₓₚ   ω     θ     κ     φ   Frames
#--------------------------------------------------------------------------
  1  ω    -32.00  30.00   0.50    1.00    --    0.00   0.00   0.00  124
;
_diffrn_measurement_device       'abstract diffractometer'
_diffrn_measurement_device_type  
'esperanto-CrysAlisPro-abstract goniometer imported esperanto images'
_diffrn_measurement_method       'ω scans'
_diffrn_orient_matrix_axis[1]    matrixX
_diffrn_orient_matrix_axis[2]    matrixY
_diffrn_orient_matrix_axis[3]    matrixZ
_diffrn_orient_matrix_type       
'CrysAlisPro convention (1999,Acta A55,543-557)'
_diffrn_orient_matrix_UB_11      -0.0089919000
_diffrn_orient_matrix_UB_12      -0.0053421000
_diffrn_orient_matrix_UB_13      -0.0303763000
_diffrn_orient_matrix_UB_21      0.0065048000
_diffrn_orient_matrix_UB_22      -0.0312773000
_diffrn_orient_matrix_UB_23      0.0035646000
_diffrn_orient_matrix_UB_31      -0.0301881000
_diffrn_orient_matrix_UB_32      -0.0051722000
_diffrn_orient_matrix_UB_33      0.0097675000
_diffrn_radiation_monochromator  synchrotron
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           synchrotron
_diffrn_radiation_wavelength     0.71075
_diffrn_source                   synchrotron
_reflns_Friedel_coverage         0.000
_reflns_Friedel_fraction_full    .
_reflns_Friedel_fraction_max     .
_reflns_number_gt                237
_reflns_number_total             371
_reflns_special_details          
;
 Reflections were merged by SHELXL according to the crystal
 class for the calculation of statistics and refinement.
 
 _reflns_Friedel_fraction is defined as the number of unique
 Friedel pairs measured divided by the number that would be
 possible theoretically, ignoring centric projections and
 systematic absences.
;
_reflns_threshold_expression     'I > 2σ(I)'
_computing_cell_refinement       'CrysAlisPro 1.171.43.70a (Rigaku OD, 2023)'
_computing_data_collection       
'CrysAlisPro 1.171.43.70a (Rigaku OD, 2023) (IMPORT)'
_computing_data_reduction        'CrysAlisPro 1.171.43.70a (Rigaku OD, 2023)'
_computing_molecular_graphics    'Olex2 1.5 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 1.5 (Dolomanov et al., 2009)'
_computing_structure_refinement  'SHELXL 2019/3 (Sheldrick, 2015)'
_computing_structure_solution    'SHELXT 2018/2 (Sheldrick, 2018)'
_refine_diff_density_max         0.349
_refine_diff_density_min         -0.132
_refine_diff_density_rms         0.068
_refine_ls_extinction_coef       .
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.064
_refine_ls_hydrogen_treatment    undef
_refine_ls_matrix_type           full
_refine_ls_number_parameters     15
_refine_ls_number_reflns         371
_refine_ls_number_restraints     0
_refine_ls_R_factor_all          0.0904
_refine_ls_R_factor_gt           0.0657
_refine_ls_restrained_S_all      1.064
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details     
'w=1/[σ²(Fo²)+(0.1255P)²+0.4645P] where P=(Fo²+2Fc²)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.2004
_refine_ls_wR_factor_ref         0.2357
_refine_special_details          ?
_olex2_refinement_description    
;
;
_atom_sites_solution_hydrogens   .
_atom_sites_solution_primary     ?
_atom_sites_solution_secondary   ?
loop_
_atom_site_label
_atom_site_type_symbol
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_U_iso_or_equiv
_atom_site_adp_type
_atom_site_occupancy
_atom_site_site_symmetry_order
_atom_site_calc_flag
_atom_site_refinement_flags_posn
_atom_site_refinement_flags_adp
_atom_site_refinement_flags_occupancy
_atom_site_disorder_assembly
_atom_site_disorder_group
O1 O 0.250000 0.000000 0.500000 0.0660(12) Uani 1 8 d S T P . .
O2 O 0.18349(12) 0.18349(12) 0.18349(12) 0.0671(10) Uani 1 3 d S T P . .
O3 O 0.000000 0.30908(18) 0.11648(18) 0.0678(9) Uani 1 2 d S T P . .
C2 C 0.000000 0.000000 0.000000 0.069(4) Uiso 0.95(3) 24 d S . . . .
C1 C 0.250000 0.500000 0.000000 0.140(4) Uiso 1 8 d S . P . .


_geom_special_details            
;
 All esds (except the esd in the dihedral angle between two l.s. planes)
 are estimated using the full covariance matrix.  The cell esds are taken
 into account individually in the estimation of esds in distances, angles
 and torsion angles; correlations between esds in cell parameters are only
 used when they are defined by crystal symmetry.  An approximate (isotropic)
 treatment of cell esds is used for estimating esds involving l.s. planes.
;
loop_
_axis.id
_axis.system
_axis.type
_axis.equipment
_axis.parity
_axis.depends_on
_axis.zero
_axis.vector[1]
_axis.vector[2]
_axis.vector[3]
source abstract . source . . . 0.99988797 0.00000000 -0.01496808
omega abstract rotation goniometer -1 . 0.74380000 0.00000000 0.00000000
1.00000000
kappa abstract rotation goniometer -1 omega 0.00084000 -0.76604444 0.00000000
0.64278761
phi abstract rotation goniometer -1 kappa . 0.00000000 0.00000000 1.00000000
theta abstract rotation goniometer -1 . -0.88015000 0.00000000 0.00000000
1.00000000
matrixX abstract general general . phi . 1.00000000 0.00000000 0.00000000
matrixY abstract general general . phi . 0.00000000 1.00000000 0.00000000
matrixZ abstract general general . phi . 0.00000000 0.00000000 1.00000000
dacX abstract translation general . phi . 0.00000000 1.00000000 0.00000000
dacY abstract translation general . phi . -1.00000000 0.00000000 0.00000000
dacZ abstract translation general . phi . 0.00000000 0.00000000 1.00000000

_olex2_submission_special_instructions 'No special instructions were received'
_oxdiff_exptl_absorpt_empirical_details 
;
Empirical correction (ABSPACK) includes:
- Absorption correction using spherical harmonics
- Frame scaling
;
_oxdiff_exptl_absorpt_empirical_full_max 1.538
_oxdiff_exptl_absorpt_empirical_full_min 0.677

data_Exp1_p5_MHIIa
_database_code_depnum_ccdc_archive 'CCDC 2521389'
loop_
_audit_author_name
_audit_author_address
'Katarzyna Skrzynska'
;ESRF
France
;
_audit_update_record             
;
2026-01-08 deposited with the CCDC.	2026-01-08 downloaded from the CCDC.
;
# start Validation Reply Form
_vrf_GEOM001_Exp1_p5_MHIIa       
;
PROBLEM: _geom_bond_atom_site_label_1 is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_GEOM002_Exp1_p5_MHIIa       
;
PROBLEM: _geom_bond_atom_site_label_2 is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_GEOM003_Exp1_p5_MHIIa       
;
PROBLEM: _geom_bond_distance is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_GEOM006_Exp1_p5_MHIIa       
;
PROBLEM: _geom_angle_atom_site_label_2 is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_GEOM007_Exp1_p5_MHIIa       
;
PROBLEM: _geom_angle_atom_site_label_3 is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_GEOM008_Exp1_p5_MHIIa       
;
PROBLEM: _geom_angle is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_PLAT029_Exp1_p5_MHIIa       
;
PROBLEM: _diffrn_measured_fraction_theta_full value Low .      0.482 Why?
RESPONSE: The low data completeness is due to the physical restrictions of the Diamond Anvil Cell and specific crystal orientation regarding to the beam.
;
_vrf_PLAT049_Exp1_p5_MHIIa       
;
PROBLEM: Calculated Density Less Than 1.0 gcm-3 .........     0.8198 Check
RESPONSE: The structure consists of an open, porous water framework containing cages populated by methane molecules, resulting in a lower density compared to compact ice phases.
;
# Added during the CSD deposition process: Thursday 08 January 2026 05:36 PM
# end Validation Reply Form

_audit_creation_date             2026-01-07
_audit_creation_method           
;
Olex2 1.5
(compiled 2025.07.13 svn.rb7424aed for OlexSys, GUI svn.r7314)
;
_shelx_SHELXL_version_number     2019/3
_audit_contact_author_address    ?
_audit_contact_author_email      ?
_audit_contact_author_phone      ?
_publ_contact_author_id_orcid    ?
_publ_section_references         
;
Dolomanov, O.V., Bourhis, L.J., Gildea, R.J, Howard, J.A.K. & Puschmann, H.
 (2009), J. Appl. Cryst. 42, 339-341.

Sheldrick, G.M. (2015). Acta Cryst. C71, 3-8.
;
_chemical_name_common            ?
_chemical_name_systematic        'methane clathrate hydrate'
_chemical_formula_moiety         '34(O), 5.692(C1)'
_chemical_formula_sum            'C5.69 O34'
_chemical_formula_weight         612.34
_chemical_melting_point          ?
loop_
_atom_type_symbol
_atom_type_description
_atom_type_scat_dispersion_real
_atom_type_scat_dispersion_imag
_atom_type_scat_source
C C 0.0033 0.0016 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
O O 0.0106 0.0060 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'

_shelx_space_group_comment       
;
The symmetry employed for this shelxl refinement is uniquely defined
by the following loop, which should always be used as a source of
symmetry information in preference to the above space-group names.
They are only intended as comments.
;
_space_group_crystal_system      hexagonal
_space_group_IT_number           191
_space_group_name_H-M_alt        'P 6/m m m'
_space_group_name_Hall           '-P 6 2'
loop_
_space_group_symop_operation_xyz
'x, y, z'
'-y, x-y, z'
'-x+y, -x, z'
'-x, -y, z'
'y, -x+y, z'
'x-y, x, z'
'y, x, -z'
'x-y, -y, -z'
'-x, -x+y, -z'
'-y, -x, -z'
'-x+y, y, -z'
'x, x-y, -z'
'-x, -y, -z'
'y, -x+y, -z'
'x-y, x, -z'
'x, y, -z'
'-y, x-y, -z'
'-x+y, -x, -z'
'-y, -x, z'
'-x+y, y, z'
'x, x-y, z'
'y, x, z'
'x-y, -y, z'
'-x, -x+y, z'

_cell_length_a                   11.9546(7)
_cell_length_b                   11.9546(7)
_cell_length_c                   10.023(6)
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                120
_cell_volume                     1240.4(7)
_cell_formula_units_Z            1
_cell_measurement_reflns_used    435
_cell_measurement_temperature    296.15
_cell_measurement_pressure       910000(20000)
_cell_measurement_theta_max      16.4310
_cell_measurement_theta_min      2.0660
_shelx_estimated_absorpt_T_max   0.991
_shelx_estimated_absorpt_T_min   0.991
_exptl_absorpt_coefficient_mu    0.094
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.11023
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   
;
CrysAlisPro 1.171.43.125a (Rigaku Oxford Diffraction, 2024)
Empirical absorption correction using spherical harmonics,
implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_absorpt_special_details   ?
_exptl_crystal_colour            ?
_exptl_crystal_density_diffrn    0.820
_exptl_crystal_density_meas      ?
_exptl_crystal_density_method    ?
_exptl_crystal_description       plate
_exptl_crystal_F_000             306
_exptl_crystal_size_max          0.03
_exptl_crystal_size_mid          0.03
_exptl_crystal_size_min          0.03
_exptl_transmission_factor_max   ?
_exptl_transmission_factor_min   ?
_diffrn_reflns_av_R_equivalents  0.0324
_diffrn_reflns_av_unetI/netI     0.0289
_diffrn_reflns_Laue_measured_fraction_full 0.482
_diffrn_reflns_Laue_measured_fraction_max 0.467
_diffrn_reflns_limit_h_max       15
_diffrn_reflns_limit_h_min       -15
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       -15
_diffrn_reflns_limit_l_max       5
_diffrn_reflns_limit_l_min       -5
_diffrn_reflns_number            2393
_diffrn_reflns_point_group_measured_fraction_full 0.482
_diffrn_reflns_point_group_measured_fraction_max 0.467
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         28.244
_diffrn_reflns_theta_min         4.432
_diffrn_ambient_temperature      296.15
_diffrn_detector                 'Hybrid Pixel Array Detector'
_diffrn_detector_area_resol_mean 13.3333
_diffrn_measured_fraction_theta_full 0.482
_diffrn_measured_fraction_theta_max 0.467
_diffrn_measurement_details      
;
List of Runs (angles in degrees, time in seconds):

  # Type    Start    End  Width  tₑₓₚ   ω     θ     κ     φ   Frames
#--------------------------------------------------------------------------
  1  ω    -32.00  30.00   0.50    1.00    --    0.00   0.00   0.00  124
;
_diffrn_measurement_device       'abstract diffractometer'
_diffrn_measurement_device_type  
'esperanto-CrysAlisPro-abstract goniometer imported esperanto images'
_diffrn_measurement_method       'ω scans'
_diffrn_orient_matrix_axis[1]    matrixX
_diffrn_orient_matrix_axis[2]    matrixY
_diffrn_orient_matrix_axis[3]    matrixZ
_diffrn_orient_matrix_type       
'CrysAlisPro convention (1999,Acta A55,543-557)'
_diffrn_orient_matrix_UB_11      0.0043714000
_diffrn_orient_matrix_UB_12      0.0042899000
_diffrn_orient_matrix_UB_13      -0.0369589000
_diffrn_orient_matrix_UB_21      0.0280562000
_diffrn_orient_matrix_UB_22      0.0332155000
_diffrn_orient_matrix_UB_23      0.0051144000
_diffrn_orient_matrix_UB_31      0.0222819000
_diffrn_orient_matrix_UB_32      -0.0134460000
_diffrn_orient_matrix_UB_33      0.0008073000
_diffrn_radiation_monochromator  synchrotron
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           synchrotron
_diffrn_radiation_wavelength     0.71075
_diffrn_source                   synchrotron
_reflns_Friedel_coverage         0.000
_reflns_Friedel_fraction_full    .
_reflns_Friedel_fraction_max     .
_reflns_number_gt                259
_reflns_number_total             310
_reflns_special_details          
;
 Reflections were merged by SHELXL according to the crystal
 class for the calculation of statistics and refinement.
 
 _reflns_Friedel_fraction is defined as the number of unique
 Friedel pairs measured divided by the number that would be
 possible theoretically, ignoring centric projections and
 systematic absences.
;
_reflns_threshold_expression     'I > 2σ(I)'
_computing_cell_refinement       'CrysAlisPro 1.171.43.125a (Rigaku OD, 2024)'
_computing_data_collection       
'CrysAlisPro 1.171.43.125a (Rigaku OD, 2024) (IMPORT)'
_computing_data_reduction        'CrysAlisPro 1.171.43.125a (Rigaku OD, 2024)'
_computing_molecular_graphics    'Olex2 1.5 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 1.5 (Dolomanov et al., 2009)'
_computing_structure_refinement  'SHELXL 2019/3 (Sheldrick, 2015)'
_computing_structure_solution    'SHELXT 2014/5 (Sheldrick, 2014)'
_refine_diff_density_max         0.232
_refine_diff_density_min         -0.164
_refine_diff_density_rms         0.044
_refine_ls_extinction_coef       .
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.152
_refine_ls_hydrogen_treatment    undef
_refine_ls_matrix_type           full
_refine_ls_number_parameters     27
_refine_ls_number_reflns         310
_refine_ls_number_restraints     0
_refine_ls_R_factor_all          0.0783
_refine_ls_R_factor_gt           0.0707
_refine_ls_restrained_S_all      1.152
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details     
'w=1/[σ²(Fo²)+(0.1663P)²+0.0847P] where P=(Fo²+2Fc²)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.2102
_refine_ls_wR_factor_ref         0.2445
_refine_special_details          ?
_olex2_refinement_description    
;
;
_atom_sites_solution_hydrogens   .
_atom_sites_solution_primary     ?
_atom_sites_solution_secondary   ?
loop_
_atom_site_label
_atom_site_type_symbol
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_U_iso_or_equiv
_atom_site_adp_type
_atom_site_occupancy
_atom_site_site_symmetry_order
_atom_site_calc_flag
_atom_site_refinement_flags_posn
_atom_site_refinement_flags_adp
_atom_site_refinement_flags_occupancy
_atom_site_disorder_assembly
_atom_site_disorder_group
O1 O 0.13295(11) 0.2659(2) 0.000000 0.060(3) Uani 1 4 d S T P . .
O2 O 0.333333 0.666667 0.1351(8) 0.062(3) Uani 1 6 d S T P . .
O3 O 0.20825(8) 0.41650(17) 0.2242(5) 0.069(2) Uani 1 2 d S T P . .
O4 O 0.3863(3) 0.000000 0.3643(7) 0.088(3) Uani 1 2 d S T P . .
C1 C 0.500000 0.000000 0.000000 0.064(3) Uiso 0.88(4) 8 d S . . . .
C2 C 0.333333 0.666667 0.500000 0.094(6) Uiso 0.92(6) 12 d S . . . .
C3 C 0.000000 0.000000 0.177(8) 0.15(2) Uiso 0.61(9) 12 d S . . . .


_geom_special_details            
;
 All esds (except the esd in the dihedral angle between two l.s. planes)
 are estimated using the full covariance matrix.  The cell esds are taken
 into account individually in the estimation of esds in distances, angles
 and torsion angles; correlations between esds in cell parameters are only
 used when they are defined by crystal symmetry.  An approximate (isotropic)
 treatment of cell esds is used for estimating esds involving l.s. planes.
;
loop_
_axis.id
_axis.system
_axis.type
_axis.equipment
_axis.parity
_axis.depends_on
_axis.zero
_axis.vector[1]
_axis.vector[2]
_axis.vector[3]
source abstract . source . . . 0.99988797 0.00000000 -0.01496808
omega abstract rotation goniometer -1 . 0.74380000 0.00000000 0.00000000
1.00000000
kappa abstract rotation goniometer -1 omega 0.00084000 -0.76604444 0.00000000
0.64278761
phi abstract rotation goniometer -1 kappa . 0.00000000 0.00000000 1.00000000
theta abstract rotation goniometer -1 . -0.88015000 0.00000000 0.00000000
1.00000000
matrixX abstract general general . phi . 1.00000000 0.00000000 0.00000000
matrixY abstract general general . phi . 0.00000000 1.00000000 0.00000000
matrixZ abstract general general . phi . 0.00000000 0.00000000 1.00000000
dacX abstract translation general . phi . 0.00000000 1.00000000 0.00000000
dacY abstract translation general . phi . -1.00000000 0.00000000 0.00000000
dacZ abstract translation general . phi . 0.00000000 0.00000000 1.00000000

_olex2_submission_special_instructions 'No special instructions were received'
_oxdiff_exptl_absorpt_empirical_details 
;
Empirical correction (ABSPACK) includes:
- Absorption correction using spherical harmonics
- Frame scaling
;
_oxdiff_exptl_absorpt_empirical_full_max 6.227
_oxdiff_exptl_absorpt_empirical_full_min 0.589

data_Exp1_p6_MHIIa
_database_code_depnum_ccdc_archive 'CCDC 2521390'
loop_
_audit_author_name
_audit_author_address
'Katarzyna Skrzynska'
;ESRF
France
;
_audit_update_record             
;
2026-01-08 deposited with the CCDC.	2026-01-08 downloaded from the CCDC.
;
# start Validation Reply Form
_vrf_GEOM001_Exp1_p6_MHIIa       
;
PROBLEM: _geom_bond_atom_site_label_1 is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_GEOM002_Exp1_p6_MHIIa       
;
PROBLEM: _geom_bond_atom_site_label_2 is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_GEOM003_Exp1_p6_MHIIa       
;
PROBLEM: _geom_bond_distance is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_GEOM006_Exp1_p6_MHIIa       
;
PROBLEM: _geom_angle_atom_site_label_2 is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_GEOM007_Exp1_p6_MHIIa       
;
PROBLEM: _geom_angle_atom_site_label_3 is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_GEOM008_Exp1_p6_MHIIa       
;
PROBLEM: _geom_angle is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_PLAT029_Exp1_p6_MHIIa       
;
PROBLEM: _diffrn_measured_fraction_theta_full value Low .      0.481 Why?
RESPONSE: The low data completeness is due to the physical restrictions of the Diamond Anvil Cell and specific crystal orientation regarding to the beam.
;
_vrf_PLAT049_Exp1_p6_MHIIa       
;
PROBLEM: Calculated Density Less Than 1.0 gcm-3 .........     0.8284 Check
RESPONSE: The structure consists of an open, porous water framework containing cages populated by methane molecules, resulting in a lower density compared to compact ice phases.
;
# Added during the CSD deposition process: Thursday 08 January 2026 05:39 PM
# end Validation Reply Form

_audit_creation_date             2025-05-16
_audit_creation_method           
;
Olex2 1.5
(compiled 2025.04.05 svn.rf049d14d for OlexSys, GUI svn.r7224)
;
_shelx_SHELXL_version_number     2019/3
_audit_contact_author_address    ?
_audit_contact_author_email      ?
_audit_contact_author_phone      ?
_publ_contact_author_id_orcid    ?
_publ_section_references         
;
Dolomanov, O.V., Bourhis, L.J., Gildea, R.J, Howard, J.A.K. & Puschmann, H.
 (2009), J. Appl. Cryst. 42, 339-341.

Sheldrick, G.M. (2015). Acta Cryst. C71, 3-8.
;
_chemical_name_common            ?
_chemical_name_systematic        'methane clathrate hydrate'
_chemical_formula_moiety         '34(O), 5.737(C)'
_chemical_formula_sum            'C5.74 O34'
_chemical_formula_weight         612.94
_chemical_melting_point          ?
_chemical_oxdiff_formula         'C H O'
loop_
_atom_type_symbol
_atom_type_description
_atom_type_scat_dispersion_real
_atom_type_scat_dispersion_imag
_atom_type_scat_source
C C -0.0004 0.0004 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
O O 0.0008 0.0015 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'

_shelx_space_group_comment       
;
The symmetry employed for this shelxl refinement is uniquely defined
by the following loop, which should always be used as a source of
symmetry information in preference to the above space-group names.
They are only intended as comments.
;
_space_group_crystal_system      hexagonal
_space_group_IT_number           191
_space_group_name_H-M_alt        'P 6/m m m'
_space_group_name_Hall           '-P 6 2'
loop_
_space_group_symop_operation_xyz
'x, y, z'
'-y, x-y, z'
'-x+y, -x, z'
'-x, -y, z'
'y, -x+y, z'
'x-y, x, z'
'y, x, -z'
'x-y, -y, -z'
'-x, -x+y, -z'
'-y, -x, -z'
'-x+y, y, -z'
'x, x-y, -z'
'-x, -y, -z'
'y, -x+y, -z'
'x-y, x, -z'
'x, y, -z'
'-y, x-y, -z'
'-x+y, -x, -z'
'-y, -x, z'
'-x+y, y, z'
'x, x-y, z'
'y, x, z'
'x-y, -y, z'
'-x, -x+y, z'

_cell_length_a                   11.9157(7)
_cell_length_b                   11.9157(7)
_cell_length_c                   9.992(5)
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                120
_cell_volume                     1228.6(7)
_cell_formula_units_Z            1
_cell_measurement_reflns_used    311
_cell_measurement_temperature    296.15
_cell_measurement_pressure       1020000(20000)
_cell_measurement_theta_max      17.2130
_cell_measurement_theta_min      1.7990
_shelx_estimated_absorpt_T_max   0.997
_shelx_estimated_absorpt_T_min   0.997
_exptl_absorpt_coefficient_mu    0.026
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.29586
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   
;
CrysAlisPro 1.171.43.70a (Rigaku Oxford Diffraction, 2023)
Empirical absorption correction using spherical harmonics,
implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_absorpt_special_details   ?
_exptl_crystal_colour            ?
_exptl_crystal_density_diffrn    0.828
_exptl_crystal_density_meas      ?
_exptl_crystal_density_method    ?
_exptl_crystal_description       plate
_exptl_crystal_F_000             306
_exptl_crystal_size_max          0.04
_exptl_crystal_size_mid          0.04
_exptl_crystal_size_min          0.03
_exptl_transmission_factor_max   ?
_exptl_transmission_factor_min   ?
_diffrn_reflns_av_R_equivalents  0.0306
_diffrn_reflns_av_unetI/netI     0.0179
_diffrn_reflns_Laue_measured_fraction_full 0.481
_diffrn_reflns_Laue_measured_fraction_max 0.467
_diffrn_reflns_limit_h_max       15
_diffrn_reflns_limit_h_min       -15
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       -15
_diffrn_reflns_limit_l_max       5
_diffrn_reflns_limit_l_min       -5
_diffrn_reflns_number            2407
_diffrn_reflns_point_group_measured_fraction_full 0.481
_diffrn_reflns_point_group_measured_fraction_max 0.467
_diffrn_reflns_theta_full        12.961
_diffrn_reflns_theta_max         14.421
_diffrn_reflns_theta_min         2.336
_diffrn_ambient_temperature      296.15
_diffrn_detector                 'Hybrid Pixel Array Detector'
_diffrn_detector_area_resol_mean 13.3333
_diffrn_measured_fraction_theta_full 0.481
_diffrn_measured_fraction_theta_max 0.467
_diffrn_measurement_details      
;
List of Runs (angles in degrees, time in seconds):

  # Type    Start    End  Width  tₑₓₚ   ω     θ     κ     φ   Frames
#--------------------------------------------------------------------------
  1  ω    -32.00  31.00   0.50    1.00    --    0.00   0.00   0.00  126
;
_diffrn_measurement_device       'abstract diffractometer'
_diffrn_measurement_device_type  
'esperanto-CrysAlisPro-abstract goniometer imported esperanto images'
_diffrn_measurement_method       'ω scans'
_diffrn_orient_matrix_axis[1]    matrixX
_diffrn_orient_matrix_axis[2]    matrixY
_diffrn_orient_matrix_axis[3]    matrixZ
_diffrn_orient_matrix_type       
'CrysAlisPro convention (1999,Acta A55,543-557)'
_diffrn_orient_matrix_UB_11      0.0045216000
_diffrn_orient_matrix_UB_12      0.0001033000
_diffrn_orient_matrix_UB_13      0.0370162000
_diffrn_orient_matrix_UB_21      0.0281501000
_diffrn_orient_matrix_UB_22      -0.0051718000
_diffrn_orient_matrix_UB_23      -0.0052951000
_diffrn_orient_matrix_UB_31      0.0223483000
_diffrn_orient_matrix_UB_32      0.0358583000
_diffrn_orient_matrix_UB_33      -0.0008505000
_diffrn_radiation_monochromator  synchrotron
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           synchrotron
_diffrn_radiation_wavelength     0.3738
_diffrn_source                   synchrotron
_reflns_Friedel_coverage         0.000
_reflns_Friedel_fraction_full    .
_reflns_Friedel_fraction_max     .
_reflns_number_gt                235
_reflns_number_total             307
_reflns_special_details          
;
 Reflections were merged by SHELXL according to the crystal
 class for the calculation of statistics and refinement.
 
 _reflns_Friedel_fraction is defined as the number of unique
 Friedel pairs measured divided by the number that would be
 possible theoretically, ignoring centric projections and
 systematic absences.
;
_reflns_threshold_expression     'I > 2σ(I)'
_computing_cell_refinement       'CrysAlisPro 1.171.43.70a (Rigaku OD, 2023)'
_computing_data_collection       
'CrysAlisPro 1.171.43.70a (Rigaku OD, 2023) (IMPORT)'
_computing_data_reduction        'CrysAlisPro 1.171.43.70a (Rigaku OD, 2023)'
_computing_molecular_graphics    'Olex2 1.5 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 1.5 (Dolomanov et al., 2009)'
_computing_structure_refinement  'SHELXL 2019/3 (Sheldrick, 2015)'
_computing_structure_solution    'SHELXT 2018/2 (Sheldrick, 2018)'
_refine_diff_density_max         0.230
_refine_diff_density_min         -0.130
_refine_diff_density_rms         0.046
_refine_ls_extinction_coef       .
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.098
_refine_ls_hydrogen_treatment    undef
_refine_ls_matrix_type           full
_refine_ls_number_parameters     27
_refine_ls_number_reflns         307
_refine_ls_number_restraints     0
_refine_ls_R_factor_all          0.0798
_refine_ls_R_factor_gt           0.0701
_refine_ls_restrained_S_all      1.098
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details     
'w=1/[σ²(Fo²)+(0.1718P)²] where P=(Fo²+2Fc²)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.2088
_refine_ls_wR_factor_ref         0.2271
_refine_special_details          ?
_olex2_refinement_description    
;
;
_atom_sites_solution_hydrogens   .
_atom_sites_solution_primary     ?
_atom_sites_solution_secondary   ?
loop_
_atom_site_label
_atom_site_type_symbol
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_U_iso_or_equiv
_atom_site_adp_type
_atom_site_occupancy
_atom_site_site_symmetry_order
_atom_site_calc_flag
_atom_site_refinement_flags_posn
_atom_site_refinement_flags_adp
_atom_site_refinement_flags_occupancy
_atom_site_disorder_assembly
_atom_site_disorder_group
O1 O 0.13293(11) 0.2659(2) 0.000000 0.056(3) Uani 1 4 d S T P . .
O2 O 0.333333 0.666667 0.1343(7) 0.057(3) Uani 1 6 d S T P . .
O3 O 0.20830(8) 0.41659(16) 0.2241(4) 0.061(2) Uani 1 2 d S T P . .
O4 O 0.3859(2) 0.000000 0.3638(6) 0.086(3) Uani 1 2 d S T P . .
C1 C 0.500000 0.000000 0.000000 0.065(3) Uiso 0.92(4) 8 d S . . . .
C2 C 0.333333 0.666667 0.500000 0.096(5) Uiso 0.91(5) 12 d S . . . .
C3 C 0.000000 0.000000 0.187(7) 0.145(17) Uiso 0.58(7) 12 d S . . . .


_geom_special_details            
;
 All esds (except the esd in the dihedral angle between two l.s. planes)
 are estimated using the full covariance matrix.  The cell esds are taken
 into account individually in the estimation of esds in distances, angles
 and torsion angles; correlations between esds in cell parameters are only
 used when they are defined by crystal symmetry.  An approximate (isotropic)
 treatment of cell esds is used for estimating esds involving l.s. planes.
;
loop_
_axis.id
_axis.system
_axis.type
_axis.equipment
_axis.parity
_axis.depends_on
_axis.zero
_axis.vector[1]
_axis.vector[2]
_axis.vector[3]
source abstract . source . . . 0.99988797 0.00000000 -0.01496808
omega abstract rotation goniometer -1 . 0.74380000 0.00000000 0.00000000
1.00000000
kappa abstract rotation goniometer -1 omega 0.00084000 -0.76604444 0.00000000
0.64278761
phi abstract rotation goniometer -1 kappa . 0.00000000 0.00000000 1.00000000
theta abstract rotation goniometer -1 . -0.88015000 0.00000000 0.00000000
1.00000000
matrixX abstract general general . phi . 1.00000000 0.00000000 0.00000000
matrixY abstract general general . phi . 0.00000000 1.00000000 0.00000000
matrixZ abstract general general . phi . 0.00000000 0.00000000 1.00000000
dacX abstract translation general . phi . 0.00000000 1.00000000 0.00000000
dacY abstract translation general . phi . -1.00000000 0.00000000 0.00000000
dacZ abstract translation general . phi . 0.00000000 0.00000000 1.00000000

_olex2_submission_special_instructions 'No special instructions were received'
_oxdiff_exptl_absorpt_empirical_details 
;
Empirical correction (ABSPACK) includes:
- Absorption correction using spherical harmonics
- Frame scaling
;
_oxdiff_exptl_absorpt_empirical_full_max 2.287
_oxdiff_exptl_absorpt_empirical_full_min 0.671

data_Exp1_p7_MHIIa
_database_code_depnum_ccdc_archive 'CCDC 2521391'
loop_
_audit_author_name
_audit_author_address
'Katarzyna Skrzynska'
;ESRF
France
;
_audit_update_record             
;
2026-01-08 deposited with the CCDC.	2026-01-08 downloaded from the CCDC.
;
# start Validation Reply Form
_vrf_PLAT029_Exp1_p7_MHIIa       
;
PROBLEM: _diffrn_measured_fraction_theta_full value Low .      0.485 Why?
RESPONSE: The low data completeness is due to the physical restrictions of the Diamond Anvil Cell and specific crystal orientation regarding to the beam.
;
_vrf_PLAT049_Exp1_p7_MHIIa       
;
PROBLEM: Calculated Density Less Than 1.0 gcm-3 .........     0.8736 Check
RESPONSE: The structure consists of an open, porous water framework containing cages populated by methane molecules, resulting in a lower density compared to compact ice phases.
;
# Added during the CSD deposition process: Thursday 08 January 2026 05:47 PM
# end Validation Reply Form

_audit_creation_date             2025-05-19
_audit_creation_method           
;
Olex2 1.5
(compiled 2025.04.05 svn.rf049d14d for OlexSys, GUI svn.r7224)
;
_shelx_SHELXL_version_number     2019/3
_audit_contact_author_address    ?
_audit_contact_author_email      ?
_audit_contact_author_phone      ?
_publ_contact_author_id_orcid    ?
_publ_section_references         
;
Dolomanov, O.V., Bourhis, L.J., Gildea, R.J, Howard, J.A.K. & Puschmann, H.
 (2009), J. Appl. Cryst. 42, 339-341.

Sheldrick, G.M. (2015). Acta Cryst. C71, 3-8.
;
_chemical_name_common            ?
_chemical_name_systematic        'methane clathrate hydrate'
_chemical_formula_moiety         '34(O), 8.096(C)'
_chemical_formula_sum            'C8.10 O34'
_chemical_formula_weight         641.28
_chemical_melting_point          ?
_chemical_oxdiff_formula         'C H O'
loop_
_atom_type_symbol
_atom_type_description
_atom_type_scat_dispersion_real
_atom_type_scat_dispersion_imag
_atom_type_scat_source
C C 0.0034 0.0017 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
O O 0.0114 0.0062 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'

_shelx_space_group_comment       
;
The symmetry employed for this shelxl refinement is uniquely defined
by the following loop, which should always be used as a source of
symmetry information in preference to the above space-group names.
They are only intended as comments.
;
_space_group_crystal_system      hexagonal
_space_group_IT_number           191
_space_group_name_H-M_alt        'P 6/m m m'
_space_group_name_Hall           '-P 6 2'
loop_
_space_group_symop_operation_xyz
'x, y, z'
'-y, x-y, z'
'-x+y, -x, z'
'-x, -y, z'
'y, -x+y, z'
'x-y, x, z'
'y, x, -z'
'x-y, -y, -z'
'-x, -x+y, -z'
'-y, -x, -z'
'-x+y, y, -z'
'x, x-y, -z'
'-x, -y, -z'
'y, -x+y, -z'
'x-y, x, -z'
'x, y, -z'
'-y, x-y, -z'
'-x+y, -x, -z'
'-y, -x, z'
'-x+y, y, z'
'x, x-y, z'
'y, x, z'
'x-y, -y, z'
'-x, -x+y, z'

_cell_length_a                   11.8754(6)
_cell_length_b                   11.8754(6)
_cell_length_c                   9.977(5)
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                120
_cell_volume                     1218.5(6)
_cell_formula_units_Z            1
_cell_measurement_reflns_used    367
_cell_measurement_temperature    296.15
_cell_measurement_pressure       1150000(20000)
_cell_measurement_theta_max      16.4740
_cell_measurement_theta_min      1.8020
_shelx_estimated_absorpt_T_max   0.990
_shelx_estimated_absorpt_T_min   0.990
_exptl_absorpt_coefficient_mu    0.097
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.44196
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   
;
CrysAlisPro 1.171.43.95a (Rigaku Oxford Diffraction, 2023)
Empirical absorption correction using spherical harmonics,
implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_absorpt_special_details   ?
_exptl_crystal_colour            ?
_exptl_crystal_density_diffrn    0.874
_exptl_crystal_density_meas      ?
_exptl_crystal_density_method    ?
_exptl_crystal_description       plate
_exptl_crystal_F_000             321
_exptl_crystal_size_max          0.04
_exptl_crystal_size_mid          0.04
_exptl_crystal_size_min          0.03
_exptl_transmission_factor_max   ?
_exptl_transmission_factor_min   ?
_diffrn_reflns_av_R_equivalents  0.0238
_diffrn_reflns_av_unetI/netI     0.0126
_diffrn_reflns_Laue_measured_fraction_full 0.485
_diffrn_reflns_Laue_measured_fraction_max 0.469
_diffrn_reflns_limit_h_max       15
_diffrn_reflns_limit_h_min       -15
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       -15
_diffrn_reflns_limit_l_max       5
_diffrn_reflns_limit_l_min       -5
_diffrn_reflns_number            2380
_diffrn_reflns_point_group_measured_fraction_full 0.485
_diffrn_reflns_point_group_measured_fraction_max 0.469
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         28.281
_diffrn_reflns_theta_min         4.459
_diffrn_ambient_temperature      296.15
_diffrn_detector_area_resol_mean 13.3333
_diffrn_measured_fraction_theta_full 0.485
_diffrn_measured_fraction_theta_max 0.469
_diffrn_measurement_details      
;
List of Runs (angles in degrees, time in seconds):

  # Type    Start    End  Width  tₑₓₚ   ω     θ     κ     φ   Frames
#--------------------------------------------------------------------------
  1  ω    -32.00  31.00   0.50    1.00    --    0.00   0.00   0.00  126
;
_diffrn_measurement_device       'abstract diffractometer'
_diffrn_measurement_device_type  
'esperanto-CrysAlisPro-abstract goniometer imported esperanto images'
_diffrn_measurement_method       'ω scans'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71075
_diffrn_source                   ?
_reflns_Friedel_coverage         0.000
_reflns_Friedel_fraction_full    .
_reflns_Friedel_fraction_max     .
_reflns_number_gt                240
_reflns_number_total             307
_reflns_special_details          
;
 Reflections were merged by SHELXL according to the crystal
 class for the calculation of statistics and refinement.
 
 _reflns_Friedel_fraction is defined as the number of unique
 Friedel pairs measured divided by the number that would be
 possible theoretically, ignoring centric projections and
 systematic absences.
;
_reflns_threshold_expression     'I > 2σ(I)'
_computing_cell_refinement       'CrysAlisPro 1.171.43.95a (Rigaku OD, 2023)'
_computing_data_collection       
'CrysAlisPro 1.171.43.95a (Rigaku OD, 2023) (IMPORT)'
_computing_data_reduction        'CrysAlisPro 1.171.43.95a (Rigaku OD, 2023)'
_computing_molecular_graphics    'Olex2 1.5 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 1.5 (Dolomanov et al., 2009)'
_computing_structure_refinement  'SHELXL 2019/3 (Sheldrick, 2015)'
_computing_structure_solution    'SHELXT 2018/2 (Sheldrick, 2018)'
_refine_diff_density_max         0.238
_refine_diff_density_min         -0.128
_refine_diff_density_rms         0.040
_refine_ls_extinction_coef       .
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.137
_refine_ls_hydrogen_treatment    undef
_refine_ls_matrix_type           full
_refine_ls_number_parameters     29
_refine_ls_number_reflns         307
_refine_ls_number_restraints     0
_refine_ls_R_factor_all          0.0758
_refine_ls_R_factor_gt           0.0674
_refine_ls_restrained_S_all      1.137
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details     
'w=1/[σ²(Fo²)+(0.1259P)²+0.1050P] where P=(Fo²+2Fc²)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1953
_refine_ls_wR_factor_ref         0.2051
_refine_special_details          ?
_olex2_refinement_description    
;
;
_atom_sites_solution_hydrogens   .
_atom_sites_solution_primary     ?
_atom_sites_solution_secondary   ?
loop_
_atom_site_label
_atom_site_type_symbol
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_U_iso_or_equiv
_atom_site_adp_type
_atom_site_occupancy
_atom_site_site_symmetry_order
_atom_site_calc_flag
_atom_site_refinement_flags_posn
_atom_site_refinement_flags_adp
_atom_site_refinement_flags_occupancy
_atom_site_disorder_assembly
_atom_site_disorder_group
O1 O 0.13328(11) 0.2666(2) 0.000000 0.060(3) Uani 1 4 d S T P . .
O2 O 0.333333 0.666667 0.1332(8) 0.065(3) Uani 1 6 d S T P . .
O3 O 0.20818(8) 0.41637(17) 0.2228(4) 0.065(2) Uani 1 2 d S T P . .
O4 O 0.3859(3) 0.000000 0.3659(7) 0.103(3) Uani 1 2 d S T P . .
C1 C 0.500000 0.000000 0.000000 0.066(3) Uiso 0.96(4) 8 d S . . . .
C2 C 0.333333 0.666667 0.500000 0.099(3) Uiso 1 12 d S . P . .
C3 C 0.000000 0.000000 0.179(6) 0.161(14) Uiso 0.85(8) 12 d S . . . .
C4 C 0.156(5) 0.000000 0.500000 0.20(4) Uiso 0.25(7) 4 d S . . . .


_geom_special_details            
;
 All esds (except the esd in the dihedral angle between two l.s. planes)
 are estimated using the full covariance matrix.  The cell esds are taken
 into account individually in the estimation of esds in distances, angles
 and torsion angles; correlations between esds in cell parameters are only
 used when they are defined by crystal symmetry.  An approximate (isotropic)
 treatment of cell esds is used for estimating esds involving l.s. planes.
;
loop_
_geom_bond_atom_site_label_1
_geom_bond_atom_site_label_2
_geom_bond_distance
_geom_bond_site_symmetry_2
_geom_bond_publ_flag
C4 C4 1.86(6) 14_556 ?
C4 C4 1.86(6) 15_556 ?

loop_
_geom_angle_atom_site_label_1
_geom_angle_atom_site_label_2
_geom_angle_atom_site_label_3
_geom_angle
_geom_angle_site_symmetry_1
_geom_angle_site_symmetry_3
_geom_angle_publ_flag
C4 C4 C4 119.998(9) 14_556 15_556 ?

_olex2_submission_special_instructions 'No special instructions were received'
_oxdiff_exptl_absorpt_empirical_details 
;
Empirical correction (ABSPACK) includes:
- Absorption correction using spherical harmonics
- Frame scaling
;
_oxdiff_exptl_absorpt_empirical_full_max 2.029
_oxdiff_exptl_absorpt_empirical_full_min 0.727

data_Exp1_p8_MHIIa
_database_code_depnum_ccdc_archive 'CCDC 2521392'
loop_
_audit_author_name
_audit_author_address
'Katarzyna Skrzynska'
;ESRF
France
;
_audit_update_record             
;
2026-01-08 deposited with the CCDC.	2026-01-08 downloaded from the CCDC.
;
# start Validation Reply Form
_vrf_PLAT029_Exp1_p8_MHIIa       
;
PROBLEM: _diffrn_measured_fraction_theta_full value Low .      0.487 Why?
RESPONSE: The low data completeness is due to the physical restrictions of the Diamond Anvil Cell and specific crystal orientation regarding to the beam.
;
_vrf_PLAT049_Exp1_p8_MHIIa       
;
PROBLEM: Calculated Density Less Than 1.0 gcm-3 .........     0.8881 Check
RESPONSE: The structure consists of an open, porous water framework containing cages populated by methane molecules, resulting in a lower density compared to compact ice phases.
;
# Added during the CSD deposition process: Thursday 08 January 2026 05:49 PM
# end Validation Reply Form

_audit_creation_date             2025-05-19
_audit_creation_method           
;
Olex2 1.5
(compiled 2025.04.05 svn.rf049d14d for OlexSys, GUI svn.r7224)
;
_shelx_SHELXL_version_number     2019/3
_audit_contact_author_address    ?
_audit_contact_author_email      ?
_audit_contact_author_phone      ?
_publ_contact_author_id_orcid    ?
_publ_section_references         
;
Dolomanov, O.V., Bourhis, L.J., Gildea, R.J, Howard, J.A.K. & Puschmann, H.
 (2009), J. Appl. Cryst. 42, 339-341.

Sheldrick, G.M. (2015). Acta Cryst. C71, 3-8.
;
_chemical_name_common            ?
_chemical_name_systematic        'methane clathrate hydrate'
_chemical_formula_moiety         '34(O), 8.63(C)'
_chemical_formula_sum            'C8.62 O34'
_chemical_formula_weight         647.53
_chemical_melting_point          ?
_chemical_oxdiff_formula         'H C O'
loop_
_atom_type_symbol
_atom_type_description
_atom_type_scat_dispersion_real
_atom_type_scat_dispersion_imag
_atom_type_scat_source
C C 0.0033 0.0016 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
O O 0.0106 0.0060 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'

_shelx_space_group_comment       
;
The symmetry employed for this shelxl refinement is uniquely defined
by the following loop, which should always be used as a source of
symmetry information in preference to the above space-group names.
They are only intended as comments.
;
_space_group_crystal_system      hexagonal
_space_group_IT_number           191
_space_group_name_H-M_alt        'P 6/m m m'
_space_group_name_Hall           '-P 6 2'
loop_
_space_group_symop_operation_xyz
'x, y, z'
'-y, x-y, z'
'-x+y, -x, z'
'-x, -y, z'
'y, -x+y, z'
'x-y, x, z'
'y, x, -z'
'x-y, -y, -z'
'-x, -x+y, -z'
'-y, -x, -z'
'-x+y, y, -z'
'x, x-y, -z'
'-x, -y, -z'
'y, -x+y, -z'
'x-y, x, -z'
'x, y, -z'
'-y, x-y, -z'
'-x+y, -x, -z'
'-y, -x, z'
'-x+y, y, z'
'x, x-y, z'
'y, x, z'
'x-y, -y, z'
'-x, -x+y, z'

_cell_length_a                   11.8363(7)
_cell_length_b                   11.8363(7)
_cell_length_c                   9.979(7)
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                120
_cell_volume                     1210.8(8)
_cell_formula_units_Z            1
_cell_measurement_reflns_used    416
_cell_measurement_temperature    296.15
_cell_measurement_pressure       1280000(20000)
_cell_measurement_theta_max      19.7600
_cell_measurement_theta_min      1.8060
_shelx_estimated_absorpt_T_max   0.990
_shelx_estimated_absorpt_T_min   0.990
_exptl_absorpt_coefficient_mu    0.099
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.26830
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   
;
CrysAlisPro 1.171.43.95a (Rigaku Oxford Diffraction, 2023)
Empirical absorption correction using spherical harmonics,
implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_absorpt_special_details   ?
_exptl_crystal_colour            ?
_exptl_crystal_density_diffrn    0.888
_exptl_crystal_density_meas      ?
_exptl_crystal_density_method    ?
_exptl_crystal_description       plate
_exptl_crystal_F_000             324
_exptl_crystal_size_max          0.04
_exptl_crystal_size_mid          0.04
_exptl_crystal_size_min          0.03
_exptl_transmission_factor_max   ?
_exptl_transmission_factor_min   ?
_diffrn_reflns_av_R_equivalents  0.0209
_diffrn_reflns_av_unetI/netI     0.0098
_diffrn_reflns_Laue_measured_fraction_full 0.487
_diffrn_reflns_Laue_measured_fraction_max 0.470
_diffrn_reflns_limit_h_max       15
_diffrn_reflns_limit_h_min       -15
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       -15
_diffrn_reflns_limit_l_max       5
_diffrn_reflns_limit_l_min       -5
_diffrn_reflns_number            2322
_diffrn_reflns_point_group_measured_fraction_full 0.487
_diffrn_reflns_point_group_measured_fraction_max 0.470
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         28.208
_diffrn_reflns_theta_min         4.471
_diffrn_ambient_temperature      296.15
_diffrn_detector                 'Hybrid Pixel Array Detector'
_diffrn_detector_area_resol_mean 13.3333
_diffrn_measured_fraction_theta_full 0.487
_diffrn_measured_fraction_theta_max 0.470
_diffrn_measurement_details      
;
List of Runs (angles in degrees, time in seconds):

  # Type    Start    End  Width  tₑₓₚ   ω     θ     κ     φ   Frames
#--------------------------------------------------------------------------
  1  ω    -32.00  30.00   0.50    2.00    --    0.00   0.00   0.00  124
;
_diffrn_measurement_device       'abstract diffractometer'
_diffrn_measurement_device_type  
'esperanto-CrysAlisPro-abstract goniometer imported esperanto images'
_diffrn_measurement_method       'ω scans'
_diffrn_orient_matrix_axis[1]    matrixX
_diffrn_orient_matrix_axis[2]    matrixY
_diffrn_orient_matrix_axis[3]    matrixZ
_diffrn_orient_matrix_type       
'CrysAlisPro convention (1999,Acta A55,543-557)'
_diffrn_orient_matrix_UB_11      0.0046067000
_diffrn_orient_matrix_UB_12      0.0045290000
_diffrn_orient_matrix_UB_13      -0.0371128000
_diffrn_orient_matrix_UB_21      0.0283154000
_diffrn_orient_matrix_UB_22      0.0334957000
_diffrn_orient_matrix_UB_23      0.0053783000
_diffrn_orient_matrix_UB_31      0.0224769000
_diffrn_orient_matrix_UB_32      -0.0135993000
_diffrn_orient_matrix_UB_33      0.0008102000
_diffrn_radiation_monochromator  synchrotron
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           synchrotron
_diffrn_radiation_wavelength     0.71075
_diffrn_source                   synchrotron
_reflns_Friedel_coverage         0.000
_reflns_Friedel_fraction_full    .
_reflns_Friedel_fraction_max     .
_reflns_number_gt                242
_reflns_number_total             306
_reflns_special_details          
;
 Reflections were merged by SHELXL according to the crystal
 class for the calculation of statistics and refinement.
 
 _reflns_Friedel_fraction is defined as the number of unique
 Friedel pairs measured divided by the number that would be
 possible theoretically, ignoring centric projections and
 systematic absences.
;
_reflns_threshold_expression     'I > 2σ(I)'
_computing_cell_refinement       'CrysAlisPro 1.171.43.95a (Rigaku OD, 2023)'
_computing_data_collection       
'CrysAlisPro 1.171.43.95a (Rigaku OD, 2023) (IMPORT)'
_computing_data_reduction        'CrysAlisPro 1.171.43.95a (Rigaku OD, 2023)'
_computing_molecular_graphics    'Olex2 1.5 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 1.5 (Dolomanov et al., 2009)'
_computing_structure_refinement  'SHELXL 2019/3 (Sheldrick, 2015)'
_computing_structure_solution    'SHELXT 2018/2 (Sheldrick, 2018)'
_refine_diff_density_max         0.243
_refine_diff_density_min         -0.137
_refine_diff_density_rms         0.047
_refine_ls_extinction_coef       .
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.058
_refine_ls_hydrogen_treatment    undef
_refine_ls_matrix_type           full
_refine_ls_number_parameters     28
_refine_ls_number_reflns         306
_refine_ls_number_restraints     0
_refine_ls_R_factor_all          0.0800
_refine_ls_R_factor_gt           0.0718
_refine_ls_restrained_S_all      1.058
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details     
'w=1/[σ²(Fo²)+(0.1599P)²+0.1147P] where P=(Fo²+2Fc²)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.2100
_refine_ls_wR_factor_ref         0.2265
_refine_special_details          ?
_olex2_refinement_description    
;
1. Uiso/Uaniso restraints and constraints
Uiso(O4A) = Uiso(O4B)
2. Others
 Sof(O4B)=0.5*(1-FVAR(2))
 Sof(O4A)=0.5*FVAR(2)
;
_atom_sites_solution_hydrogens   .
_atom_sites_solution_primary     ?
_atom_sites_solution_secondary   ?
loop_
_atom_site_label
_atom_site_type_symbol
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_U_iso_or_equiv
_atom_site_adp_type
_atom_site_occupancy
_atom_site_site_symmetry_order
_atom_site_calc_flag
_atom_site_refinement_flags_posn
_atom_site_refinement_flags_adp
_atom_site_refinement_flags_occupancy
_atom_site_disorder_assembly
_atom_site_disorder_group
O1 O 0.13366(12) 0.2673(2) 0.000000 0.060(2) Uani 1 4 d S T P . .
O2 O 0.333333 0.666667 0.1326(7) 0.057(3) Uani 1 6 d S T P . .
O3 O 0.20833(9) 0.41665(18) 0.2240(4) 0.064(2) Uani 1 2 d S T P . .
O4A O 0.4087(5) 0.000000 0.3649(9) 0.0640(11) Uiso 0.524(6) 2 d S . P . .
O4B O 0.3596(6) 0.000000 0.3669(10) 0.0640(11) Uiso 0.476(6) 2 d S . P . .
C1 C 0.500000 0.000000 0.000000 0.068(3) Uiso 1.00(4) 8 d S . . . .
C2 C 0.333333 0.666667 0.500000 0.095(3) Uiso 1 12 d S . P . .
C3 C 0.000000 0.000000 0.188(5) 0.153(7) Uiso 1 12 d S . P . .
C4 C 0.169(4) 0.000000 0.500000 0.15(2) Uiso 0.27(5) 4 d S . . . .


_geom_special_details            
;
 All esds (except the esd in the dihedral angle between two l.s. planes)
 are estimated using the full covariance matrix.  The cell esds are taken
 into account individually in the estimation of esds in distances, angles
 and torsion angles; correlations between esds in cell parameters are only
 used when they are defined by crystal symmetry.  An approximate (isotropic)
 treatment of cell esds is used for estimating esds involving l.s. planes.
;
loop_
_geom_bond_atom_site_label_1
_geom_bond_atom_site_label_2
_geom_bond_distance
_geom_bond_site_symmetry_2
_geom_bond_publ_flag
O4A O4B 0.582(4) . ?
C4 C4 2.00(4) 15_556 ?
C4 C4 2.00(4) 14_556 ?

loop_
_geom_angle_atom_site_label_1
_geom_angle_atom_site_label_2
_geom_angle_atom_site_label_3
_geom_angle
_geom_angle_site_symmetry_1
_geom_angle_site_symmetry_3
_geom_angle_publ_flag
C4 C4 C4 119.999(7) 14_556 15_556 ?

loop_
_axis.id
_axis.system
_axis.type
_axis.equipment
_axis.parity
_axis.depends_on
_axis.zero
_axis.vector[1]
_axis.vector[2]
_axis.vector[3]
source abstract . source . . . 0.99988797 0.00000000 -0.01496808
omega abstract rotation goniometer -1 . 0.74380000 0.00000000 0.00000000
1.00000000
kappa abstract rotation goniometer -1 omega 0.00084000 -0.76604444 0.00000000
0.64278761
phi abstract rotation goniometer -1 kappa . 0.00000000 0.00000000 1.00000000
theta abstract rotation goniometer -1 . -0.88015000 0.00000000 0.00000000
1.00000000
matrixX abstract general general . phi . 1.00000000 0.00000000 0.00000000
matrixY abstract general general . phi . 0.00000000 1.00000000 0.00000000
matrixZ abstract general general . phi . 0.00000000 0.00000000 1.00000000
dacX abstract translation general . phi . 0.00000000 1.00000000 0.00000000
dacY abstract translation general . phi . -1.00000000 0.00000000 0.00000000
dacZ abstract translation general . phi . 0.00000000 0.00000000 1.00000000

_olex2_submission_special_instructions 'No special instructions were received'
_oxdiff_exptl_absorpt_empirical_details 
;
Empirical correction (ABSPACK) includes:
- Absorption correction using spherical harmonics
- Frame scaling
;
_oxdiff_exptl_absorpt_empirical_full_max 2.720
_oxdiff_exptl_absorpt_empirical_full_min 0.710

data_Exp1_p9_MHIIb
_database_code_depnum_ccdc_archive 'CCDC 2521393'
loop_
_audit_author_name
_audit_author_address
'Katarzyna Skrzynska'
;ESRF
France
;
_audit_update_record             
;
2026-01-09 deposited with the CCDC.	2026-01-09 downloaded from the CCDC.
;
# start Validation Reply Form
_vrf_GEOM001_Exp1_p9_MHIIb       
;
PROBLEM: _geom_bond_atom_site_label_1 is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_GEOM002_Exp1_p9_MHIIb       
;
PROBLEM: _geom_bond_atom_site_label_2 is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_GEOM003_Exp1_p9_MHIIb       
;
PROBLEM: _geom_bond_distance is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_GEOM006_Exp1_p9_MHIIb       
;
PROBLEM: _geom_angle_atom_site_label_2 is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_GEOM007_Exp1_p9_MHIIb       
;
PROBLEM: _geom_angle_atom_site_label_3 is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_GEOM008_Exp1_p9_MHIIb       
;
PROBLEM: _geom_angle is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_PLAT029_Exp1_p9_MHIIb       
;
PROBLEM: _diffrn_measured_fraction_theta_full value Low .      0.467 Why?
RESPONSE: The low data completeness is due to the physical restrictions of the Diamond Anvil Cell and specific crystal orientation regarding to the beam
;
_vrf_PLAT049_Exp1_p9_MHIIb       
;
PROBLEM: Calculated Density Less Than 1.0 gcm-3 .........     0.8999 Check
RESPONSE: The structure consists of an open, porous water framework containing cages populated by methane molecules, resulting in a lower density compared to compact ice phases.
;
# Added during the CSD deposition process: Friday 09 January 2026 09:03 AM
# end Validation Reply Form

_audit_creation_date             2025-05-16
_audit_creation_method           
;
Olex2 1.5
(compiled 2025.04.05 svn.rf049d14d for OlexSys, GUI svn.r7224)
;
_shelx_SHELXL_version_number     2019/3
_audit_contact_author_address    ?
_audit_contact_author_email      ?
_audit_contact_author_phone      ?
_publ_contact_author_id_orcid    ?
_publ_section_references         
;
Dolomanov, O.V., Bourhis, L.J., Gildea, R.J, Howard, J.A.K. & Puschmann, H.
 (2009), J. Appl. Cryst. 42, 339-341.

Sheldrick, G.M. (2015). Acta Cryst. C71, 3-8.
;
_chemical_name_common            ?
_chemical_name_systematic        'methane clathrate hydrate'
_chemical_formula_moiety         '34(O), 8.974(C)'
_chemical_formula_sum            'C8.97 O34'
_chemical_formula_weight         651.73
_chemical_absolute_configuration ?
_chemical_melting_point          ?
_chemical_oxdiff_formula         'C H O'
loop_
_atom_type_symbol
_atom_type_description
_atom_type_scat_dispersion_real
_atom_type_scat_dispersion_imag
_atom_type_scat_source
C C 0.0033 0.0016 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
O O 0.0106 0.0060 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'

_shelx_space_group_comment       
;
The symmetry employed for this shelxl refinement is uniquely defined
by the following loop, which should always be used as a source of
symmetry information in preference to the above space-group names.
They are only intended as comments.
;
_space_group_crystal_system      hexagonal
_space_group_IT_number           189
_space_group_name_H-M_alt        'P -6 2 m'
_space_group_name_Hall           'P -6 -2'
loop_
_space_group_symop_operation_xyz
'x, y, z'
'-y, x-y, z'
'-x+y, -x, z'
'x, y, -z'
'-y, x-y, -z'
'-x+y, -x, -z'
'y, x, -z'
'x-y, -y, -z'
'-x, -x+y, -z'
'y, x, z'
'x-y, -y, z'
'-x, -x+y, z'

_cell_length_a                   11.8153(7)
_cell_length_b                   11.8153(7)
_cell_length_c                   9.949(5)
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                120
_cell_volume                     1202.8(6)
_cell_formula_units_Z            1
_cell_measurement_reflns_used    423
_cell_measurement_temperature    296.15
_cell_measurement_pressure       1440000(20000)
_cell_measurement_theta_max      18.8630
_cell_measurement_theta_min      1.8100
_shelx_estimated_absorpt_T_max   0.990
_shelx_estimated_absorpt_T_min   0.990
_exptl_absorpt_coefficient_mu    0.100
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.04759
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   
;
CrysAlisPro 1.171.43.95a (Rigaku Oxford Diffraction, 2023)
Empirical absorption correction using spherical harmonics,
implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_absorpt_special_details   ?
_exptl_crystal_colour            ?
_exptl_crystal_density_diffrn    0.900
_exptl_crystal_density_meas      ?
_exptl_crystal_density_method    ?
_exptl_crystal_description       plate
_exptl_crystal_F_000             326
_exptl_crystal_size_max          0.04
_exptl_crystal_size_mid          0.04
_exptl_crystal_size_min          0.03
_exptl_transmission_factor_max   ?
_exptl_transmission_factor_min   ?
_diffrn_reflns_av_R_equivalents  0.0281
_diffrn_reflns_av_unetI/netI     0.0176
_diffrn_reflns_Laue_measured_fraction_full 0.467
_diffrn_reflns_Laue_measured_fraction_max 0.456
_diffrn_reflns_limit_h_max       15
_diffrn_reflns_limit_h_min       -15
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       -15
_diffrn_reflns_limit_l_max       5
_diffrn_reflns_limit_l_min       -5
_diffrn_reflns_number            2248
_diffrn_reflns_point_group_measured_fraction_full 0.482
_diffrn_reflns_point_group_measured_fraction_max 0.468
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         28.266
_diffrn_reflns_theta_min         4.480
_diffrn_ambient_temperature      296.15
_diffrn_detector                 'Hybrid Pixel Array Detector'
_diffrn_detector_area_resol_mean 13.3333
_diffrn_measured_fraction_theta_full 0.467
_diffrn_measured_fraction_theta_max 0.456
_diffrn_measurement_details      
;
List of Runs (angles in degrees, time in seconds):

  # Type    Start    End  Width  tₑₓₚ   ω     θ     κ     φ   Frames
#--------------------------------------------------------------------------
  1  ω    -32.00  31.00   0.50    2.00    --    0.00   0.00   0.00  126
;
_diffrn_measurement_device       'abstract diffractometer'
_diffrn_measurement_device_type  
'esperanto-CrysAlisPro-abstract goniometer imported esperanto images'
_diffrn_measurement_method       'ω scans'
_diffrn_orient_matrix_axis[1]    matrixX
_diffrn_orient_matrix_axis[2]    matrixY
_diffrn_orient_matrix_axis[3]    matrixZ
_diffrn_orient_matrix_type       
'CrysAlisPro convention (1999,Acta A55,543-557)'
_diffrn_orient_matrix_UB_11      0.0046523000
_diffrn_orient_matrix_UB_12      0.0045798000
_diffrn_orient_matrix_UB_13      -0.0371656000
_diffrn_orient_matrix_UB_21      0.0283763000
_diffrn_orient_matrix_UB_22      0.0335704000
_diffrn_orient_matrix_UB_23      0.0054495000
_diffrn_orient_matrix_UB_31      0.0225239000
_diffrn_orient_matrix_UB_32      -0.0136453000
_diffrn_orient_matrix_UB_33      0.0008401000
_diffrn_radiation_monochromator  synchrotron
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           synchrotron
_diffrn_radiation_wavelength     0.71075
_diffrn_source                   synchrotron
_reflns_Friedel_coverage         0.808
_reflns_Friedel_fraction_full    0.503
_reflns_Friedel_fraction_max     0.484
_reflns_number_gt                442
_reflns_number_total             537
_reflns_special_details          
;
 Reflections were merged by SHELXL according to the crystal
 class for the calculation of statistics and refinement.
 
 _reflns_Friedel_fraction is defined as the number of unique
 Friedel pairs measured divided by the number that would be
 possible theoretically, ignoring centric projections and
 systematic absences.
;
_reflns_threshold_expression     'I > 2σ(I)'
_computing_cell_refinement       'CrysAlisPro 1.171.43.95a (Rigaku OD, 2023)'
_computing_data_collection       
'CrysAlisPro 1.171.43.95a (Rigaku OD, 2023) (IMPORT)'
_computing_data_reduction        'CrysAlisPro 1.171.43.95a (Rigaku OD, 2023)'
_computing_molecular_graphics    'Olex2 1.5 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 1.5 (Dolomanov et al., 2009)'
_computing_structure_refinement  'SHELXL 2019/3 (Sheldrick, 2015)'
_computing_structure_solution    'SHELXT 2018/2 (Sheldrick, 2018)'
_refine_diff_density_max         0.272
_refine_diff_density_min         -0.239
_refine_diff_density_rms         0.068
_refine_ls_abs_structure_details 
;
 Flack x determined using 178 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   -0.6(10)
_refine_ls_extinction_coef       .
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.090
_refine_ls_hydrogen_treatment    undef
_refine_ls_matrix_type           full
_refine_ls_number_parameters     39
_refine_ls_number_reflns         537
_refine_ls_number_restraints     0
_refine_ls_R_factor_all          0.1011
_refine_ls_R_factor_gt           0.0923
_refine_ls_restrained_S_all      1.090
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details     
'w=1/[σ²(Fo²)+(0.1799P)²+0.0720P] where P=(Fo²+2Fc²)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.2242
_refine_ls_wR_factor_ref         0.2390
_refine_special_details          ?
_olex2_refinement_description    
;
;
_atom_sites_solution_hydrogens   .
_atom_sites_solution_primary     ?
_atom_sites_solution_secondary   ?
loop_
_atom_site_label
_atom_site_type_symbol
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_U_iso_or_equiv
_atom_site_adp_type
_atom_site_occupancy
_atom_site_site_symmetry_order
_atom_site_calc_flag
_atom_site_refinement_flags_posn
_atom_site_refinement_flags_adp
_atom_site_refinement_flags_occupancy
_atom_site_disorder_assembly
_atom_site_disorder_group
O1 O 0.1331(4) 0.2680(3) 0.500000 0.062(4) Uani 1 2 d S T P . .
O2 O 0.333333 0.666667 0.3671(12) 0.051(5) Uani 1 3 d S T P . .
O3 O 0.2039(4) 0.4172(3) 0.2746(8) 0.064(3) Uani 1 1 d . . . . .
O4 O 0.6423(7) 0.000000 0.1335(15) 0.076(6) Uani 1 2 d S T P . .
O5 O 0.4146(7) 0.000000 0.138(2) 0.070(5) Uani 1 2 d S T P . .
C1 C 0.5056(11) 0.000000 0.500000 0.058(2) Uiso 1 4 d S . P . .
C2 C 0.333333 0.666667 0.000000 0.083(4) Uiso 1 6 d S . P . .
C4 C 0.181(4) 0.000000 0.000000 0.127(16) Uiso 0.66(7) 4 d S . . . .
C3 C 0.000000 0.000000 0.690(7) 0.126(8) Uiso 1 6 d S . P . .


_geom_special_details            
;
 All esds (except the esd in the dihedral angle between two l.s. planes)
 are estimated using the full covariance matrix.  The cell esds are taken
 into account individually in the estimation of esds in distances, angles
 and torsion angles; correlations between esds in cell parameters are only
 used when they are defined by crystal symmetry.  An approximate (isotropic)
 treatment of cell esds is used for estimating esds involving l.s. planes.
;
loop_
_axis.id
_axis.system
_axis.type
_axis.equipment
_axis.parity
_axis.depends_on
_axis.zero
_axis.vector[1]
_axis.vector[2]
_axis.vector[3]
source abstract . source . . . 0.99988797 0.00000000 -0.01496808
omega abstract rotation goniometer -1 . 0.74380000 0.00000000 0.00000000
1.00000000
kappa abstract rotation goniometer -1 omega 0.00084000 -0.76604444 0.00000000
0.64278761
phi abstract rotation goniometer -1 kappa . 0.00000000 0.00000000 1.00000000
theta abstract rotation goniometer -1 . -0.88015000 0.00000000 0.00000000
1.00000000
matrixX abstract general general . phi . 1.00000000 0.00000000 0.00000000
matrixY abstract general general . phi . 0.00000000 1.00000000 0.00000000
matrixZ abstract general general . phi . 0.00000000 0.00000000 1.00000000
dacX abstract translation general . phi . 0.00000000 1.00000000 0.00000000
dacY abstract translation general . phi . -1.00000000 0.00000000 0.00000000
dacZ abstract translation general . phi . 0.00000000 0.00000000 1.00000000

_olex2_submission_special_instructions 'No special instructions were received'
_oxdiff_exptl_absorpt_empirical_details 
;
Empirical correction (ABSPACK) includes:
- Absorption correction using spherical harmonics
- Frame scaling
;
_oxdiff_exptl_absorpt_empirical_full_max 15.801
_oxdiff_exptl_absorpt_empirical_full_min 0.744

data_Exp1_p10_MHIIb
_database_code_depnum_ccdc_archive 'CCDC 2521394'
loop_
_audit_author_name
_audit_author_address
'Katarzyna Skrzynska'
;ESRF
France
;
_audit_update_record             
;
2026-01-09 deposited with the CCDC.	2026-01-09 downloaded from the CCDC.
;
# start Validation Reply Form
_vrf_GEOM001_Exp1_p10_MHIIb      
;
PROBLEM: _geom_bond_atom_site_label_1 is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_GEOM002_Exp1_p10_MHIIb      
;
PROBLEM: _geom_bond_atom_site_label_2 is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_GEOM003_Exp1_p10_MHIIb      
;
PROBLEM: _geom_bond_distance is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_GEOM006_Exp1_p10_MHIIb      
;
PROBLEM: _geom_angle_atom_site_label_2 is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_GEOM007_Exp1_p10_MHIIb      
;
PROBLEM: _geom_angle_atom_site_label_3 is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_GEOM008_Exp1_p10_MHIIb      
;
PROBLEM: _geom_angle is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_PLAT029_Exp1_p10_MHIIb      
;
PROBLEM: _diffrn_measured_fraction_theta_full value Low .      0.485 Why?
RESPONSE: The low data completeness is due to the physical restrictions of the Diamond Anvil Cell and specific crystal orientation regarding to the beam.
;
_vrf_PLAT049_Exp1_p10_MHIIb      
;
PROBLEM: Calculated Density Less Than 1.0 gcm-3 .........     0.9182 Check
RESPONSE: The structure consists of an open, porous water framework containing cages populated by methane molecules, resulting in a lower density compared to compact ice phases.
;
# Added during the CSD deposition process: Friday 09 January 2026 09:06 AM
# end Validation Reply Form

_audit_creation_date             2025-05-16
_audit_creation_method           
;
Olex2 1.5
(compiled 2025.04.05 svn.rf049d14d for OlexSys, GUI svn.r7224)
;
_shelx_SHELXL_version_number     2019/3
_audit_contact_author_address    ?
_audit_contact_author_email      ?
_audit_contact_author_phone      ?
_publ_contact_author_id_orcid    ?
_publ_section_references         
;
Dolomanov, O.V., Bourhis, L.J., Gildea, R.J, Howard, J.A.K. & Puschmann, H.
 (2009), J. Appl. Cryst. 42, 339-341.

Sheldrick, G.M. (2015). Acta Cryst. C71, 3-8.
;
_chemical_name_common            ?
_chemical_name_systematic        'methane clathrate hydrate'
_chemical_formula_moiety         '34(O), 9.804(C)'
_chemical_formula_sum            'C9.80 O34'
_chemical_formula_weight         661.70
_chemical_absolute_configuration ?
_chemical_melting_point          ?
_chemical_oxdiff_formula         'C H O'
loop_
_atom_type_symbol
_atom_type_description
_atom_type_scat_dispersion_real
_atom_type_scat_dispersion_imag
_atom_type_scat_source
C C 0.0033 0.0016 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
O O 0.0106 0.0060 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'

_shelx_space_group_comment       
;
The symmetry employed for this shelxl refinement is uniquely defined
by the following loop, which should always be used as a source of
symmetry information in preference to the above space-group names.
They are only intended as comments.
;
_space_group_crystal_system      hexagonal
_space_group_IT_number           189
_space_group_name_H-M_alt        'P -6 2 m'
_space_group_name_Hall           'P -6 -2'
loop_
_space_group_symop_operation_xyz
'x, y, z'
'-y, x-y, z'
'-x+y, -x, z'
'x, y, -z'
'-y, x-y, -z'
'-x+y, -x, -z'
'y, x, -z'
'x-y, -y, -z'
'-x, -x+y, -z'
'y, x, z'
'x-y, -y, z'
'-x, -x+y, z'

_cell_length_a                   11.8007(4)
_cell_length_b                   11.8007(4)
_cell_length_c                   9.921(4)
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                120
_cell_volume                     1196.4(4)
_cell_formula_units_Z            1
_cell_measurement_reflns_used    481
_cell_measurement_temperature    296.15
_cell_measurement_pressure       1540000(20000)
_cell_measurement_theta_max      20.6920
_cell_measurement_theta_min      1.8160
_shelx_estimated_absorpt_T_max   0.990
_shelx_estimated_absorpt_T_min   0.990
_exptl_absorpt_coefficient_mu    0.102
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.25725
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   
;
CrysAlisPro 1.171.43.95a (Rigaku Oxford Diffraction, 2023)
Empirical absorption correction using spherical harmonics,
implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_absorpt_special_details   ?
_exptl_crystal_colour            ?
_exptl_crystal_density_diffrn    0.918
_exptl_crystal_density_meas      ?
_exptl_crystal_density_method    ?
_exptl_crystal_description       plate
_exptl_crystal_F_000             331
_exptl_crystal_size_max          0.04
_exptl_crystal_size_mid          0.04
_exptl_crystal_size_min          0.03
_exptl_transmission_factor_max   ?
_exptl_transmission_factor_min   ?
_diffrn_reflns_av_R_equivalents  0.0190
_diffrn_reflns_av_unetI/netI     0.0148
_diffrn_reflns_Laue_measured_fraction_full 0.485
_diffrn_reflns_Laue_measured_fraction_max 0.472
_diffrn_reflns_limit_h_max       15
_diffrn_reflns_limit_h_min       -15
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       -15
_diffrn_reflns_limit_l_max       5
_diffrn_reflns_limit_l_min       -5
_diffrn_reflns_number            2304
_diffrn_reflns_point_group_measured_fraction_full 0.499
_diffrn_reflns_point_group_measured_fraction_max 0.486
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         28.248
_diffrn_reflns_theta_min         4.487
_diffrn_ambient_temperature      296.15
_diffrn_detector                 'Hybrid Pixel Array Detector'
_diffrn_detector_area_resol_mean 13.3333
_diffrn_measured_fraction_theta_full 0.485
_diffrn_measured_fraction_theta_max 0.472
_diffrn_measurement_details      
;
List of Runs (angles in degrees, time in seconds):

  # Type    Start    End  Width  tₑₓₚ   ω     θ     κ     φ   Frames
#--------------------------------------------------------------------------
  1  ω    -32.00  31.00   0.50    2.00    --    0.00   0.00   0.00  126
;
_diffrn_measurement_device       'abstract diffractometer'
_diffrn_measurement_device_type  
'esperanto-CrysAlisPro-abstract goniometer imported esperanto images'
_diffrn_measurement_method       'ω scans'
_diffrn_orient_matrix_axis[1]    matrixX
_diffrn_orient_matrix_axis[2]    matrixY
_diffrn_orient_matrix_axis[3]    matrixZ
_diffrn_orient_matrix_type       
'CrysAlisPro convention (1999,Acta A55,543-557)'
_diffrn_orient_matrix_UB_11      0.0047058000
_diffrn_orient_matrix_UB_12      0.0046111000
_diffrn_orient_matrix_UB_13      -0.0373024000
_diffrn_orient_matrix_UB_21      0.0284095000
_diffrn_orient_matrix_UB_22      0.0335878000
_diffrn_orient_matrix_UB_23      0.0054720000
_diffrn_orient_matrix_UB_31      0.0225313000
_diffrn_orient_matrix_UB_32      -0.0136649000
_diffrn_orient_matrix_UB_33      0.0008476000
_diffrn_radiation_monochromator  synchrotron
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           synchrotron
_diffrn_radiation_wavelength     0.71075
_diffrn_source                   synchrotron
_reflns_Friedel_coverage         0.816
_reflns_Friedel_fraction_full    0.518
_reflns_Friedel_fraction_max     0.505
_reflns_number_gt                482
_reflns_number_total             554
_reflns_special_details          
;
 Reflections were merged by SHELXL according to the crystal
 class for the calculation of statistics and refinement.
 
 _reflns_Friedel_fraction is defined as the number of unique
 Friedel pairs measured divided by the number that would be
 possible theoretically, ignoring centric projections and
 systematic absences.
;
_reflns_threshold_expression     'I > 2σ(I)'
_computing_cell_refinement       'CrysAlisPro 1.171.43.95a (Rigaku OD, 2023)'
_computing_data_collection       
'CrysAlisPro 1.171.43.95a (Rigaku OD, 2023) (IMPORT)'
_computing_data_reduction        'CrysAlisPro 1.171.43.95a (Rigaku OD, 2023)'
_computing_molecular_graphics    'Olex2 1.5 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 1.5 (Dolomanov et al., 2009)'
_computing_structure_refinement  'SHELXL 2019/3 (Sheldrick, 2015)'
_computing_structure_solution    'SHELXT 2018/2 (Sheldrick, 2018)'
_refine_diff_density_max         0.235
_refine_diff_density_min         -0.208
_refine_diff_density_rms         0.063
_refine_ls_abs_structure_details 
;
 Flack x determined using 197 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   -3.9(10)
_refine_ls_extinction_coef       .
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.085
_refine_ls_hydrogen_treatment    undef
_refine_ls_matrix_type           full
_refine_ls_number_parameters     39
_refine_ls_number_reflns         554
_refine_ls_number_restraints     0
_refine_ls_R_factor_all          0.0800
_refine_ls_R_factor_gt           0.0745
_refine_ls_restrained_S_all      1.085
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details     
'w=1/[σ²(Fo²)+(0.1591P)²+0.0669P] where P=(Fo²+2Fc²)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1949
_refine_ls_wR_factor_ref         0.2075
_refine_special_details          ?
_olex2_refinement_description    
;
;
_atom_sites_solution_hydrogens   .
_atom_sites_solution_primary     ?
_atom_sites_solution_secondary   ?
loop_
_atom_site_label
_atom_site_type_symbol
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_U_iso_or_equiv
_atom_site_adp_type
_atom_site_occupancy
_atom_site_site_symmetry_order
_atom_site_calc_flag
_atom_site_refinement_flags_posn
_atom_site_refinement_flags_adp
_atom_site_refinement_flags_occupancy
_atom_site_disorder_assembly
_atom_site_disorder_group
O1 O 0.1325(3) 0.2677(3) 0.500000 0.057(4) Uani 1 2 d S T P . .
O2 O 0.333333 0.666667 0.3669(13) 0.056(4) Uani 1 3 d S T P . .
O3 O 0.1983(3) 0.4169(3) 0.2748(8) 0.060(3) Uani 1 1 d . . . . .
O4 O 0.6487(4) 0.000000 0.1372(12) 0.070(5) Uani 1 2 d S T P . .
O5 O 0.4200(4) 0.000000 0.1389(15) 0.060(4) Uani 1 2 d S T P . .
C1 C 0.5090(8) 0.000000 0.500000 0.058(2) Uiso 1 4 d S . P . .
C2 C 0.333333 0.666667 0.000000 0.079(4) Uiso 1 6 d S . P . .
C4 C 0.1809(15) 0.000000 0.000000 0.104(7) Uiso 0.93(5) 4 d S . . . .
C3 C 0.000000 0.000000 0.694(6) 0.136(9) Uiso 1 6 d S . P . .


_geom_special_details            
;
 All esds (except the esd in the dihedral angle between two l.s. planes)
 are estimated using the full covariance matrix.  The cell esds are taken
 into account individually in the estimation of esds in distances, angles
 and torsion angles; correlations between esds in cell parameters are only
 used when they are defined by crystal symmetry.  An approximate (isotropic)
 treatment of cell esds is used for estimating esds involving l.s. planes.
;
loop_
_axis.id
_axis.system
_axis.type
_axis.equipment
_axis.parity
_axis.depends_on
_axis.zero
_axis.vector[1]
_axis.vector[2]
_axis.vector[3]
source abstract . source . . . 0.99988797 0.00000000 -0.01496808
omega abstract rotation goniometer -1 . 0.74380000 0.00000000 0.00000000
1.00000000
kappa abstract rotation goniometer -1 omega 0.00084000 -0.76604444 0.00000000
0.64278761
phi abstract rotation goniometer -1 kappa . 0.00000000 0.00000000 1.00000000
theta abstract rotation goniometer -1 . -0.88015000 0.00000000 0.00000000
1.00000000
matrixX abstract general general . phi . 1.00000000 0.00000000 0.00000000
matrixY abstract general general . phi . 0.00000000 1.00000000 0.00000000
matrixZ abstract general general . phi . 0.00000000 0.00000000 1.00000000
dacX abstract translation general . phi . 0.00000000 1.00000000 0.00000000
dacY abstract translation general . phi . -1.00000000 0.00000000 0.00000000
dacZ abstract translation general . phi . 0.00000000 0.00000000 1.00000000

_olex2_submission_special_instructions 'No special instructions were received'
_oxdiff_exptl_absorpt_empirical_details 
;
Empirical correction (ABSPACK) includes:
- Absorption correction using spherical harmonics
- Frame scaling
;
_oxdiff_exptl_absorpt_empirical_full_max 3.017
_oxdiff_exptl_absorpt_empirical_full_min 0.765

data_Exp1_p11_MHIIb
_database_code_depnum_ccdc_archive 'CCDC 2521395'
loop_
_audit_author_name
_audit_author_address
'Katarzyna Skrzynska'
;ESRF
France
;
_audit_update_record             
;
2026-01-09 deposited with the CCDC.	2026-01-09 downloaded from the CCDC.
;
# start Validation Reply Form
_vrf_GEOM001_Exp1_p11_MHIIb      
;
PROBLEM: _geom_bond_atom_site_label_1 is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_GEOM002_Exp1_p11_MHIIb      
;
PROBLEM: _geom_bond_atom_site_label_2 is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_GEOM003_Exp1_p11_MHIIb      
;
PROBLEM: _geom_bond_distance is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_GEOM006_Exp1_p11_MHIIb      
;
PROBLEM: _geom_angle_atom_site_label_2 is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_GEOM007_Exp1_p11_MHIIb      
;
PROBLEM: _geom_angle_atom_site_label_3 is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_GEOM008_Exp1_p11_MHIIb      
;
PROBLEM: _geom_angle is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_PLAT029_Exp1_p11_MHIIb      
;
PROBLEM: _diffrn_measured_fraction_theta_full value Low .      0.484 Why?
RESPONSE: The low data completeness is due to the physical restrictions of the Diamond Anvil Cell and specific crystal orientation regarding to the beam.
;
_vrf_PLAT049_Exp1_p11_MHIIb      
;
PROBLEM: Calculated Density Less Than 1.0 gcm-3 .........     0.9277 Check
RESPONSE: The structure consists of an open, porous water framework containing cages populated by methane molecules, resulting in a lower density compared to compact ice phases.
;
# Added during the CSD deposition process: Friday 09 January 2026 09:09 AM
# end Validation Reply Form

_audit_creation_date             2025-05-16
_audit_creation_method           
;
Olex2 1.5
(compiled 2025.04.05 svn.rf049d14d for OlexSys, GUI svn.r7224)
;
_shelx_SHELXL_version_number     2019/3
_audit_contact_author_address    ?
_audit_contact_author_email      ?
_audit_contact_author_phone      ?
_publ_contact_author_id_orcid    ?
_publ_section_references         
;
Dolomanov, O.V., Bourhis, L.J., Gildea, R.J, Howard, J.A.K. & Puschmann, H.
 (2009), J. Appl. Cryst. 42, 339-341.

Sheldrick, G.M. (2015). Acta Cryst. C71, 3-8.
;
_chemical_name_common            ?
_chemical_name_systematic        'methane clathrate hydrate'
_chemical_formula_moiety         '34(O), 10(C)'
_chemical_formula_sum            'C10 O34'
_chemical_formula_weight         664.10
_chemical_absolute_configuration ?
_chemical_melting_point          ?
loop_
_atom_type_symbol
_atom_type_description
_atom_type_scat_dispersion_real
_atom_type_scat_dispersion_imag
_atom_type_scat_source
O O 0.0106 0.0060 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
C C 0.0033 0.0016 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'

_shelx_space_group_comment       
;
The symmetry employed for this shelxl refinement is uniquely defined
by the following loop, which should always be used as a source of
symmetry information in preference to the above space-group names.
They are only intended as comments.
;
_space_group_crystal_system      hexagonal
_space_group_IT_number           189
_space_group_name_H-M_alt        'P -6 2 m'
_space_group_name_Hall           'P -6 -2'
loop_
_space_group_symop_operation_xyz
'x, y, z'
'-y, x-y, z'
'-x+y, -x, z'
'x, y, -z'
'-y, x-y, -z'
'-x+y, -x, -z'
'y, x, -z'
'x-y, -y, -z'
'-x, -x+y, -z'
'y, x, z'
'x-y, -y, z'
'-x, -x+y, z'

_cell_length_a                   11.7769(6)
_cell_length_b                   11.7769(6)
_cell_length_c                   9.896(4)
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                120
_cell_volume                     1188.7(5)
_cell_formula_units_Z            1
_cell_measurement_reflns_used    529
_cell_measurement_temperature    296.15
_cell_measurement_pressure       1660000(20000)
_cell_measurement_theta_max      17.0560
_cell_measurement_theta_min      1.8150
_shelx_estimated_absorpt_T_max   0.990
_shelx_estimated_absorpt_T_min   0.990
_exptl_absorpt_coefficient_mu    0.103
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.44456
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   
;
CrysAlisPro 1.171.43.95a (Rigaku Oxford Diffraction, 2023)
Empirical absorption correction using spherical harmonics,
implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_absorpt_special_details   ?
_exptl_crystal_colour            ?
_exptl_crystal_density_diffrn    0.928
_exptl_crystal_density_meas      ?
_exptl_crystal_density_method    ?
_exptl_crystal_description       plate
_exptl_crystal_F_000             332
_exptl_crystal_size_max          0.04
_exptl_crystal_size_mid          0.04
_exptl_crystal_size_min          0.03
_exptl_transmission_factor_max   ?
_exptl_transmission_factor_min   ?
_diffrn_reflns_av_R_equivalents  0.0161
_diffrn_reflns_av_unetI/netI     0.0118
_diffrn_reflns_Laue_measured_fraction_full 0.484
_diffrn_reflns_Laue_measured_fraction_max 0.476
_diffrn_reflns_limit_h_max       15
_diffrn_reflns_limit_h_min       -15
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       -15
_diffrn_reflns_limit_l_max       5
_diffrn_reflns_limit_l_min       -5
_diffrn_reflns_number            2258
_diffrn_reflns_point_group_measured_fraction_full 0.499
_diffrn_reflns_point_group_measured_fraction_max 0.492
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         28.253
_diffrn_reflns_theta_min         4.496
_diffrn_ambient_temperature      296.15
_diffrn_detector                 'Hybrid Pixel Array Detector'
_diffrn_detector_area_resol_mean 13.3333
_diffrn_measured_fraction_theta_full 0.484
_diffrn_measured_fraction_theta_max 0.476
_diffrn_measurement_details      
;
List of Runs (angles in degrees, time in seconds):

  # Type    Start    End  Width  tₑₓₚ   ω     θ     κ     φ   Frames
#--------------------------------------------------------------------------
  1  ω    -32.00  31.00   0.50    2.00    --    0.00   0.00   0.00  126
;
_diffrn_measurement_device       'abstract diffractometer'
_diffrn_measurement_device_type  
'esperanto-CrysAlisPro-abstract goniometer imported esperanto images'
_diffrn_measurement_method       'ω scans'
_diffrn_orient_matrix_axis[1]    matrixX
_diffrn_orient_matrix_axis[2]    matrixY
_diffrn_orient_matrix_axis[3]    matrixZ
_diffrn_orient_matrix_type       
'CrysAlisPro convention (1999,Acta A55,543-557)'
_diffrn_orient_matrix_UB_11      -0.0001524000
_diffrn_orient_matrix_UB_12      0.0045979000
_diffrn_orient_matrix_UB_13      0.0374113000
_diffrn_orient_matrix_UB_21      0.0052022000
_diffrn_orient_matrix_UB_22      0.0336542000
_diffrn_orient_matrix_UB_23      -0.0054929000
_diffrn_orient_matrix_UB_31      -0.0362562000
_diffrn_orient_matrix_UB_32      -0.0136800000
_diffrn_orient_matrix_UB_33      -0.0009373000
_diffrn_radiation_monochromator  synchrotron
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           synchrotron
_diffrn_radiation_wavelength     0.71075
_diffrn_source                   synchrotron
_reflns_Friedel_coverage         0.819
_reflns_Friedel_fraction_full    0.520
_reflns_Friedel_fraction_max     0.512
_reflns_number_gt                499
_reflns_number_total             553
_reflns_special_details          
;
 Reflections were merged by SHELXL according to the crystal
 class for the calculation of statistics and refinement.
 
 _reflns_Friedel_fraction is defined as the number of unique
 Friedel pairs measured divided by the number that would be
 possible theoretically, ignoring centric projections and
 systematic absences.
;
_reflns_threshold_expression     'I > 2σ(I)'
_computing_cell_refinement       'CrysAlisPro 1.171.43.95a (Rigaku OD, 2023)'
_computing_data_collection       
'CrysAlisPro 1.171.43.95a (Rigaku OD, 2023) (IMPORT)'
_computing_data_reduction        'CrysAlisPro 1.171.43.95a (Rigaku OD, 2023)'
_computing_molecular_graphics    'Olex2 1.5 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 1.5 (Dolomanov et al., 2009)'
_computing_structure_refinement  'SHELXL 2019/3 (Sheldrick, 2015)'
_computing_structure_solution    'SHELXT 2018/2 (Sheldrick, 2018)'
_refine_diff_density_max         0.270
_refine_diff_density_min         -0.217
_refine_diff_density_rms         0.065
_refine_ls_abs_structure_details 
;
 Flack x determined using 204 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   2.7(10)
_refine_ls_extinction_coef       .
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.078
_refine_ls_hydrogen_treatment    undef
_refine_ls_matrix_type           full
_refine_ls_number_parameters     38
_refine_ls_number_reflns         553
_refine_ls_number_restraints     0
_refine_ls_R_factor_all          0.0726
_refine_ls_R_factor_gt           0.0691
_refine_ls_restrained_S_all      1.078
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details     
'w=1/[σ²(Fo²)+(0.1474P)²+0.0190P] where P=(Fo²+2Fc²)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1748
_refine_ls_wR_factor_ref         0.1815
_refine_special_details          ?
_olex2_refinement_description    
;
;
_atom_sites_solution_hydrogens   .
_atom_sites_solution_primary     ?
_atom_sites_solution_secondary   ?
loop_
_atom_site_label
_atom_site_type_symbol
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_U_iso_or_equiv
_atom_site_adp_type
_atom_site_occupancy
_atom_site_site_symmetry_order
_atom_site_calc_flag
_atom_site_refinement_flags_posn
_atom_site_refinement_flags_adp
_atom_site_refinement_flags_occupancy
_atom_site_disorder_assembly
_atom_site_disorder_group
O1 O 0.1324(3) 0.2680(3) 0.500000 0.051(3) Uani 1 2 d S T P . .
O2 O 0.333333 0.666667 0.3662(11) 0.051(4) Uani 1 3 d S T P . .
O3 O 0.1969(3) 0.4176(2) 0.2750(7) 0.055(3) Uani 1 1 d . . . . .
O4 O 0.6527(3) 0.000000 0.1369(9) 0.057(4) Uani 1 2 d S T P . .
O5 O 0.4236(3) 0.000000 0.1386(12) 0.053(4) Uani 1 2 d S T P . .
C1 C 0.5092(7) 0.000000 0.500000 0.0552(17) Uiso 1 4 d S . P . .
C2 C 0.333333 0.666667 0.000000 0.076(3) Uiso 1 6 d S . P . .
C4 C 0.1822(10) 0.000000 0.000000 0.093(4) Uiso 1 4 d S . P . .
C3 C 0.000000 0.000000 0.671(5) 0.115(6) Uiso 1 6 d S . P . .


_geom_special_details            
;
 All esds (except the esd in the dihedral angle between two l.s. planes)
 are estimated using the full covariance matrix.  The cell esds are taken
 into account individually in the estimation of esds in distances, angles
 and torsion angles; correlations between esds in cell parameters are only
 used when they are defined by crystal symmetry.  An approximate (isotropic)
 treatment of cell esds is used for estimating esds involving l.s. planes.
;
loop_
_axis.id
_axis.system
_axis.type
_axis.equipment
_axis.parity
_axis.depends_on
_axis.zero
_axis.vector[1]
_axis.vector[2]
_axis.vector[3]
source abstract . source . . . 0.99988797 0.00000000 -0.01496808
omega abstract rotation goniometer -1 . 0.74380000 0.00000000 0.00000000
1.00000000
kappa abstract rotation goniometer -1 omega 0.00084000 -0.76604444 0.00000000
0.64278761
phi abstract rotation goniometer -1 kappa . 0.00000000 0.00000000 1.00000000
theta abstract rotation goniometer -1 . -0.88015000 0.00000000 0.00000000
1.00000000
matrixX abstract general general . phi . 1.00000000 0.00000000 0.00000000
matrixY abstract general general . phi . 0.00000000 1.00000000 0.00000000
matrixZ abstract general general . phi . 0.00000000 0.00000000 1.00000000
dacX abstract translation general . phi . 0.00000000 1.00000000 0.00000000
dacY abstract translation general . phi . -1.00000000 0.00000000 0.00000000
dacZ abstract translation general . phi . 0.00000000 0.00000000 1.00000000

_olex2_submission_special_instructions 'No special instructions were received'
_oxdiff_exptl_absorpt_empirical_details 
;
Empirical correction (ABSPACK) includes:
- Absorption correction using spherical harmonics
- Frame scaling
- Detector area scaling
;
_oxdiff_exptl_absorpt_empirical_full_max 1.945
_oxdiff_exptl_absorpt_empirical_full_min 0.827

data_Exp1_p12_MHIIb
_database_code_depnum_ccdc_archive 'CCDC 2521396'
loop_
_audit_author_name
_audit_author_address
'Katarzyna Skrzynska'
;ESRF
France
;
_audit_update_record             
;
2026-01-09 deposited with the CCDC.	2026-01-09 downloaded from the CCDC.
;
# start Validation Reply Form
_vrf_GEOM001_Exp1_p12_MHIIb      
;
PROBLEM: _geom_bond_atom_site_label_1 is missing
RESPONSE: https://doi.org/10.15151/ESRF-ES-1803920850
;
_vrf_GEOM002_Exp1_p12_MHIIb      
;
PROBLEM: _geom_bond_atom_site_label_2 is missing
RESPONSE: https://doi.org/10.15151/ESRF-ES-1803920850
;
_vrf_GEOM003_Exp1_p12_MHIIb      
;
PROBLEM: _geom_bond_distance is missing
RESPONSE: https://doi.org/10.15151/ESRF-ES-1803920850
;
_vrf_GEOM006_Exp1_p12_MHIIb      
;
PROBLEM: _geom_angle_atom_site_label_2 is missing
RESPONSE: https://doi.org/10.15151/ESRF-ES-1803920850
;
_vrf_GEOM007_Exp1_p12_MHIIb      
;
PROBLEM: _geom_angle_atom_site_label_3 is missing
RESPONSE: https://doi.org/10.15151/ESRF-ES-1803920850
;
_vrf_GEOM008_Exp1_p12_MHIIb      
;
PROBLEM: _geom_angle is missing
RESPONSE: https://doi.org/10.15151/ESRF-ES-1803920850
;
_vrf_PLAT029_Exp1_p12_MHIIb      
;
PROBLEM: _diffrn_measured_fraction_theta_full value Low .      0.492 Why?
RESPONSE: The low data completeness is due to the physical restrictions of the Diamond Anvil Cell and specific crystal orientation regarding to the beam.
;
_vrf_PLAT049_Exp1_p12_MHIIb      
;
PROBLEM: Calculated Density Less Than 1.0 gcm-3 .........     0.9372 Check
RESPONSE: The structure consists of an open, porous water framework containing cages populated by methane molecules, resulting in a lower density compared to compact ice phases.
;
# Added during the CSD deposition process: Friday 09 January 2026 09:12 AM
# end Validation Reply Form

_audit_creation_date             2025-05-16
_audit_creation_method           
;
Olex2 1.5
(compiled 2025.04.05 svn.rf049d14d for OlexSys, GUI svn.r7224)
;
_shelx_SHELXL_version_number     2019/3
_audit_contact_author_address    ?
_audit_contact_author_email      ?
_audit_contact_author_phone      ?
_publ_contact_author_id_orcid    ?
_publ_section_references         
;
Dolomanov, O.V., Bourhis, L.J., Gildea, R.J, Howard, J.A.K. & Puschmann, H.
 (2009), J. Appl. Cryst. 42, 339-341.

Sheldrick, G.M. (2015). Acta Cryst. C71, 3-8.
;
_chemical_name_common            ?
_chemical_name_systematic        'methane clathrate hydrate'
_chemical_formula_moiety         '34(O), 10(C)'
_chemical_formula_sum            'C10 O34'
_chemical_formula_weight         664.10
_chemical_absolute_configuration ?
_chemical_melting_point          ?
loop_
_atom_type_symbol
_atom_type_description
_atom_type_scat_dispersion_real
_atom_type_scat_dispersion_imag
_atom_type_scat_source
O O 0.0106 0.0060 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
C C 0.0033 0.0016 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'

_shelx_space_group_comment       
;
The symmetry employed for this shelxl refinement is uniquely defined
by the following loop, which should always be used as a source of
symmetry information in preference to the above space-group names.
They are only intended as comments.
;
_space_group_crystal_system      hexagonal
_space_group_IT_number           189
_space_group_name_H-M_alt        'P -6 2 m'
_space_group_name_Hall           'P -6 -2'
loop_
_space_group_symop_operation_xyz
'x, y, z'
'-y, x-y, z'
'-x+y, -x, z'
'x, y, -z'
'-y, x-y, -z'
'-x+y, -x, -z'
'y, x, -z'
'x-y, -y, -z'
'-x, -x+y, -z'
'y, x, z'
'x-y, -y, z'
'-x, -x+y, z'

_cell_length_a                   11.7269(7)
_cell_length_b                   11.7269(7)
_cell_length_c                   9.880(5)
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                120
_cell_volume                     1176.7(6)
_cell_formula_units_Z            1
_cell_measurement_reflns_used    767
_cell_measurement_temperature    296.15
_cell_measurement_pressure       1790000(20000)
_cell_measurement_theta_max      19.4100
_cell_measurement_theta_min      1.8210
_shelx_estimated_absorpt_T_max   0.990
_shelx_estimated_absorpt_T_min   0.990
_exptl_absorpt_coefficient_mu    0.104
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.22913
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   
;
CrysAlisPro 1.171.43.125a (Rigaku Oxford Diffraction, 2024)
Empirical absorption correction using spherical harmonics,
implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_absorpt_special_details   ?
_exptl_crystal_colour            ?
_exptl_crystal_density_diffrn    0.937
_exptl_crystal_density_meas      ?
_exptl_crystal_density_method    ?
_exptl_crystal_description       plate
_exptl_crystal_F_000             332
_exptl_crystal_size_max          0.04
_exptl_crystal_size_mid          0.04
_exptl_crystal_size_min          0.03
_exptl_transmission_factor_max   ?
_exptl_transmission_factor_min   ?
_diffrn_reflns_av_R_equivalents  0.0257
_diffrn_reflns_av_unetI/netI     0.0309
_diffrn_reflns_Laue_measured_fraction_full 0.492
_diffrn_reflns_Laue_measured_fraction_max 0.476
_diffrn_reflns_limit_h_max       15
_diffrn_reflns_limit_h_min       -15
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       -15
_diffrn_reflns_limit_l_max       5
_diffrn_reflns_limit_l_min       -5
_diffrn_reflns_number            2235
_diffrn_reflns_point_group_measured_fraction_full 0.498
_diffrn_reflns_point_group_measured_fraction_max 0.483
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         28.253
_diffrn_reflns_theta_min         4.513
_diffrn_ambient_temperature      296.15
_diffrn_detector                 'Hybrid Pixel Array Detector'
_diffrn_detector_area_resol_mean 13.3333
_diffrn_measured_fraction_theta_full 0.492
_diffrn_measured_fraction_theta_max 0.476
_diffrn_measurement_details      
;
List of Runs (angles in degrees, time in seconds):

  # Type    Start    End  Width  tₑₓₚ   ω     θ     κ     φ   Frames
#--------------------------------------------------------------------------
  1  ω    -32.00  30.00   0.50    2.00    --    0.00   0.00   0.00  124
;
_diffrn_measurement_device       'abstract diffractometer'
_diffrn_measurement_device_type  
'esperanto-CrysAlisPro-abstract goniometer imported esperanto images'
_diffrn_measurement_method       'ω scans'
_diffrn_orient_matrix_axis[1]    matrixX
_diffrn_orient_matrix_axis[2]    matrixY
_diffrn_orient_matrix_axis[3]    matrixZ
_diffrn_orient_matrix_type       
'CrysAlisPro convention (1999,Acta A55,543-557)'
_diffrn_orient_matrix_UB_11      -0.0002418000
_diffrn_orient_matrix_UB_12      0.0047541000
_diffrn_orient_matrix_UB_13      0.0375092000
_diffrn_orient_matrix_UB_21      0.0049526000
_diffrn_orient_matrix_UB_22      0.0336407000
_diffrn_orient_matrix_UB_23      -0.0056997000
_diffrn_orient_matrix_UB_31      -0.0364078000
_diffrn_orient_matrix_UB_32      -0.0139900000
_diffrn_orient_matrix_UB_33      -0.0009805000
_diffrn_radiation_monochromator  synchrotron
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           synchrotron
_diffrn_radiation_wavelength     0.71075
_diffrn_source                   synchrotron
_reflns_Friedel_coverage         0.788
_reflns_Friedel_fraction_full    0.506
_reflns_Friedel_fraction_max     0.494
_reflns_number_gt                467
_reflns_number_total             540
_reflns_special_details          
;
 Reflections were merged by SHELXL according to the crystal
 class for the calculation of statistics and refinement.
 
 _reflns_Friedel_fraction is defined as the number of unique
 Friedel pairs measured divided by the number that would be
 possible theoretically, ignoring centric projections and
 systematic absences.
;
_reflns_threshold_expression     'I > 2σ(I)'
_computing_cell_refinement       'CrysAlisPro 1.171.43.125a (Rigaku OD, 2024)'
_computing_data_collection       
'CrysAlisPro 1.171.43.125a (Rigaku OD, 2024) (IMPORT)'
_computing_data_reduction        'CrysAlisPro 1.171.43.125a (Rigaku OD, 2024)'
_computing_molecular_graphics    'Olex2 1.5 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 1.5 (Dolomanov et al., 2009)'
_computing_structure_refinement  'SHELXL 2019/3 (Sheldrick, 2015)'
_computing_structure_solution    'SHELXT 2014/5 (Sheldrick, 2014)'
_refine_diff_density_max         0.283
_refine_diff_density_min         -0.258
_refine_diff_density_rms         0.073
_refine_ls_abs_structure_details 
;
 Flack x determined using 184 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   0.6(10)
_refine_ls_extinction_coef       .
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.130
_refine_ls_hydrogen_treatment    undef
_refine_ls_matrix_type           full
_refine_ls_number_parameters     38
_refine_ls_number_reflns         540
_refine_ls_number_restraints     0
_refine_ls_R_factor_all          0.0797
_refine_ls_R_factor_gt           0.0732
_refine_ls_restrained_S_all      1.130
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details     
'w=1/[σ²(Fo²)+(0.1489P)²] where P=(Fo²+2Fc²)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1852
_refine_ls_wR_factor_ref         0.1962
_refine_special_details          ?
_olex2_refinement_description    
;
;
_atom_sites_solution_hydrogens   .
_atom_sites_solution_primary     ?
_atom_sites_solution_secondary   ?
loop_
_atom_site_label
_atom_site_type_symbol
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_U_iso_or_equiv
_atom_site_adp_type
_atom_site_occupancy
_atom_site_site_symmetry_order
_atom_site_calc_flag
_atom_site_refinement_flags_posn
_atom_site_refinement_flags_adp
_atom_site_refinement_flags_occupancy
_atom_site_disorder_assembly
_atom_site_disorder_group
O1 O 0.1327(3) 0.2679(3) 0.500000 0.045(4) Uani 1 2 d S T P . .
O2 O 0.333333 0.666667 0.3673(13) 0.050(4) Uani 1 3 d S T P . .
O3 O 0.1964(3) 0.4176(2) 0.2755(8) 0.049(3) Uani 1 1 d . . . . .
O4 O 0.6542(4) 0.000000 0.1364(10) 0.049(5) Uani 1 2 d S T P . .
O5 O 0.4251(3) 0.000000 0.1388(12) 0.048(4) Uani 1 2 d S T P . .
C1 C 0.5093(7) 0.000000 0.500000 0.058(2) Uiso 1 4 d S . P . .
C2 C 0.333333 0.666667 0.000000 0.080(4) Uiso 1 6 d S . P . .
C4 C 0.1835(10) 0.000000 0.000000 0.089(4) Uiso 1 4 d S . P . .
C3 C 0.000000 0.000000 0.675(6) 0.114(6) Uiso 1 6 d S . P . .


_geom_special_details            
;
 All esds (except the esd in the dihedral angle between two l.s. planes)
 are estimated using the full covariance matrix.  The cell esds are taken
 into account individually in the estimation of esds in distances, angles
 and torsion angles; correlations between esds in cell parameters are only
 used when they are defined by crystal symmetry.  An approximate (isotropic)
 treatment of cell esds is used for estimating esds involving l.s. planes.
;
loop_
_axis.id
_axis.system
_axis.type
_axis.equipment
_axis.parity
_axis.depends_on
_axis.zero
_axis.vector[1]
_axis.vector[2]
_axis.vector[3]
source abstract . source . . . 0.99988797 0.00000000 -0.01496808
omega abstract rotation goniometer -1 . 0.74380000 0.00000000 0.00000000
1.00000000
kappa abstract rotation goniometer -1 omega 0.00084000 -0.76604444 0.00000000
0.64278761
phi abstract rotation goniometer -1 kappa . 0.00000000 0.00000000 1.00000000
theta abstract rotation goniometer -1 . -0.88015000 0.00000000 0.00000000
1.00000000
matrixX abstract general general . phi . 1.00000000 0.00000000 0.00000000
matrixY abstract general general . phi . 0.00000000 1.00000000 0.00000000
matrixZ abstract general general . phi . 0.00000000 0.00000000 1.00000000
dacX abstract translation general . phi . 0.00000000 1.00000000 0.00000000
dacY abstract translation general . phi . -1.00000000 0.00000000 0.00000000
dacZ abstract translation general . phi . 0.00000000 0.00000000 1.00000000

_olex2_submission_special_instructions 'No special instructions were received'
_oxdiff_exptl_absorpt_empirical_details 
;
Empirical correction (ABSPACK) includes:
- Absorption correction using spherical harmonics
- Frame scaling
;
_oxdiff_exptl_absorpt_empirical_full_max 2.562
_oxdiff_exptl_absorpt_empirical_full_min 0.617

data_Exp1_p13_MHIIb
_database_code_depnum_ccdc_archive 'CCDC 2521397'
loop_
_audit_author_name
_audit_author_address
'Katarzyna Skrzynska'
;ESRF
France
;
_audit_update_record             
;
2026-01-09 deposited with the CCDC.	2026-01-09 downloaded from the CCDC.
;
# start Validation Reply Form
_vrf_GEOM001_Exp1_p13_MHIIb      
;
PROBLEM: _geom_bond_atom_site_label_1 is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_GEOM002_Exp1_p13_MHIIb      
;
PROBLEM: _geom_bond_atom_site_label_2 is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_GEOM003_Exp1_p13_MHIIb      
;
PROBLEM: _geom_bond_distance is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_GEOM006_Exp1_p13_MHIIb      
;
PROBLEM: _geom_angle_atom_site_label_2 is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_GEOM007_Exp1_p13_MHIIb      
;
PROBLEM: _geom_angle_atom_site_label_3 is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_GEOM008_Exp1_p13_MHIIb      
;
PROBLEM: _geom_angle is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_PLAT029_Exp1_p13_MHIIb      
;
PROBLEM: _diffrn_measured_fraction_theta_full value Low .      0.486 Why?
RESPONSE: The low data completeness is due to the physical restrictions of the Diamond Anvil Cell and specific crystal orientation regarding to the beam.
;
_vrf_PLAT049_Exp1_p13_MHIIb      
;
PROBLEM: Calculated Density Less Than 1.0 gcm-3 .........     0.9469 Check
RESPONSE: The structure consists of an open, porous water framework containing cages populated by methane molecules, resulting in a lower density compared to compact ice phases.
;
# Added during the CSD deposition process: Friday 09 January 2026 09:15 AM
# end Validation Reply Form

_audit_creation_date             2025-05-16
_audit_creation_method           
;
Olex2 1.5
(compiled 2025.04.05 svn.rf049d14d for OlexSys, GUI svn.r7224)
;
_shelx_SHELXL_version_number     2019/3
_audit_contact_author_address    ?
_audit_contact_author_email      ?
_audit_contact_author_phone      ?
_publ_contact_author_id_orcid    ?
_publ_section_references         
;
Dolomanov, O.V., Bourhis, L.J., Gildea, R.J, Howard, J.A.K. & Puschmann, H.
 (2009), J. Appl. Cryst. 42, 339-341.

Sheldrick, G.M. (2015). Acta Cryst. C71, 3-8.
;
_chemical_name_common            ?
_chemical_name_systematic        'methane clathrate hydrate'
_chemical_formula_moiety         '34(O), 10(C)'
_chemical_formula_sum            'C10 O34'
_chemical_formula_weight         664.10
_chemical_absolute_configuration ?
_chemical_melting_point          ?
loop_
_atom_type_symbol
_atom_type_description
_atom_type_scat_dispersion_real
_atom_type_scat_dispersion_imag
_atom_type_scat_source
O O 0.0106 0.0060 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
C C 0.0033 0.0016 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'

_shelx_space_group_comment       
;
The symmetry employed for this shelxl refinement is uniquely defined
by the following loop, which should always be used as a source of
symmetry information in preference to the above space-group names.
They are only intended as comments.
;
_space_group_crystal_system      hexagonal
_space_group_IT_number           189
_space_group_name_H-M_alt        'P -6 2 m'
_space_group_name_Hall           'P -6 -2'
loop_
_space_group_symop_operation_xyz
'x, y, z'
'-y, x-y, z'
'-x+y, -x, z'
'x, y, -z'
'-y, x-y, -z'
'-x+y, -x, -z'
'y, x, -z'
'x-y, -y, -z'
'-x, -x+y, -z'
'y, x, z'
'x-y, -y, z'
'-x, -x+y, z'

_cell_length_a                   11.6903(5)
_cell_length_b                   11.6903(5)
_cell_length_c                   9.840(4)
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                120
_cell_volume                     1164.6(5)
_cell_formula_units_Z            1
_cell_measurement_reflns_used    841
_cell_measurement_temperature    296.15
_cell_measurement_pressure       1950000(20000)
_cell_measurement_theta_max      21.2240
_cell_measurement_theta_min      1.8290
_shelx_estimated_absorpt_T_max   0.990
_shelx_estimated_absorpt_T_min   0.990
_exptl_absorpt_coefficient_mu    0.105
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.29215
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   
;
CrysAlisPro 1.171.43.125a (Rigaku Oxford Diffraction, 2024)
Empirical absorption correction using spherical harmonics,
implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_absorpt_special_details   ?
_exptl_crystal_colour            ?
_exptl_crystal_density_diffrn    0.947
_exptl_crystal_density_meas      ?
_exptl_crystal_density_method    ?
_exptl_crystal_description       plate
_exptl_crystal_F_000             332
_exptl_crystal_size_max          0.04
_exptl_crystal_size_mid          0.04
_exptl_crystal_size_min          0.03
_exptl_transmission_factor_max   ?
_exptl_transmission_factor_min   ?
_diffrn_reflns_av_R_equivalents  0.0274
_diffrn_reflns_av_unetI/netI     0.0273
_diffrn_reflns_Laue_measured_fraction_full 0.486
_diffrn_reflns_Laue_measured_fraction_max 0.476
_diffrn_reflns_limit_h_max       15
_diffrn_reflns_limit_h_min       -15
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       -15
_diffrn_reflns_limit_l_max       5
_diffrn_reflns_limit_l_min       -5
_diffrn_reflns_number            2174
_diffrn_reflns_point_group_measured_fraction_full 0.491
_diffrn_reflns_point_group_measured_fraction_max 0.482
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         28.270
_diffrn_reflns_theta_min         4.528
_diffrn_ambient_temperature      296.15
_diffrn_detector                 'Hybrid Pixel Array Detector'
_diffrn_detector_area_resol_mean 13.3333
_diffrn_measured_fraction_theta_full 0.486
_diffrn_measured_fraction_theta_max 0.476
_diffrn_measurement_details      
;
List of Runs (angles in degrees, time in seconds):

  # Type    Start    End  Width  tₑₓₚ   ω     θ     κ     φ   Frames
#--------------------------------------------------------------------------
  1  ω    -32.00  30.00   0.50    2.00    --    0.00   0.00   0.00  124
;
_diffrn_measurement_device       'abstract diffractometer'
_diffrn_measurement_device_type  
'esperanto-CrysAlisPro-abstract goniometer imported esperanto images'
_diffrn_measurement_method       'ω scans'
_diffrn_orient_matrix_axis[1]    matrixX
_diffrn_orient_matrix_axis[2]    matrixY
_diffrn_orient_matrix_axis[3]    matrixZ
_diffrn_orient_matrix_type       
'CrysAlisPro convention (1999,Acta A55,543-557)'
_diffrn_orient_matrix_UB_11      0.0047800000
_diffrn_orient_matrix_UB_12      -0.0002896000
_diffrn_orient_matrix_UB_13      -0.0375934000
_diffrn_orient_matrix_UB_21      0.0337633000
_diffrn_orient_matrix_UB_22      0.0049458000
_diffrn_orient_matrix_UB_23      0.0057601000
_diffrn_orient_matrix_UB_31      -0.0140666000
_diffrn_orient_matrix_UB_32      -0.0365477000
_diffrn_orient_matrix_UB_33      0.0010067000
_diffrn_radiation_monochromator  synchrotron
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           synchrotron
_diffrn_radiation_wavelength     0.71075
_diffrn_source                   synchrotron
_reflns_Friedel_coverage         0.783
_reflns_Friedel_fraction_full    0.497
_reflns_Friedel_fraction_max     0.491
_reflns_number_gt                461
_reflns_number_total             535
_reflns_special_details          
;
 Reflections were merged by SHELXL according to the crystal
 class for the calculation of statistics and refinement.
 
 _reflns_Friedel_fraction is defined as the number of unique
 Friedel pairs measured divided by the number that would be
 possible theoretically, ignoring centric projections and
 systematic absences.
;
_reflns_threshold_expression     'I > 2σ(I)'
_computing_cell_refinement       'CrysAlisPro 1.171.43.125a (Rigaku OD, 2024)'
_computing_data_collection       
'CrysAlisPro 1.171.43.125a (Rigaku OD, 2024) (IMPORT)'
_computing_data_reduction        'CrysAlisPro 1.171.43.125a (Rigaku OD, 2024)'
_computing_molecular_graphics    'Olex2 1.5 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 1.5 (Dolomanov et al., 2009)'
_computing_structure_refinement  'SHELXL 2019/3 (Sheldrick, 2015)'
_computing_structure_solution    'SHELXT 2014/5 (Sheldrick, 2014)'
_refine_diff_density_max         0.248
_refine_diff_density_min         -0.206
_refine_diff_density_rms         0.070
_refine_ls_abs_structure_details 
;
 Flack x determined using 179 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   -2.5(10)
_refine_ls_extinction_coef       .
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.062
_refine_ls_hydrogen_treatment    undef
_refine_ls_matrix_type           full
_refine_ls_number_parameters     38
_refine_ls_number_reflns         535
_refine_ls_number_restraints     0
_refine_ls_R_factor_all          0.0773
_refine_ls_R_factor_gt           0.0711
_refine_ls_restrained_S_all      1.062
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details     
'w=1/[σ²(Fo²)+(0.1491P)²] where P=(Fo²+2Fc²)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1775
_refine_ls_wR_factor_ref         0.1873
_refine_special_details          ?
_olex2_refinement_description    
;
;
_atom_sites_solution_hydrogens   .
_atom_sites_solution_primary     ?
_atom_sites_solution_secondary   ?
loop_
_atom_site_label
_atom_site_type_symbol
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_U_iso_or_equiv
_atom_site_adp_type
_atom_site_occupancy
_atom_site_site_symmetry_order
_atom_site_calc_flag
_atom_site_refinement_flags_posn
_atom_site_refinement_flags_adp
_atom_site_refinement_flags_occupancy
_atom_site_disorder_assembly
_atom_site_disorder_group
O1 O 0.1329(3) 0.2682(3) 0.500000 0.051(4) Uani 1 2 d S T P . .
O2 O 0.333333 0.666667 0.3667(13) 0.057(4) Uani 1 3 d S T P . .
O3 O 0.1958(3) 0.4174(2) 0.2752(7) 0.056(3) Uani 1 1 d . . . . .
O4 O 0.6556(4) 0.000000 0.1366(9) 0.058(5) Uani 1 2 d S T P . .
O5 O 0.4258(3) 0.000000 0.1371(12) 0.059(4) Uani 1 2 d S T P . .
C1 C 0.5098(7) 0.000000 0.500000 0.0569(19) Uiso 1 4 d S . P . .
C2 C 0.333333 0.666667 0.000000 0.078(3) Uiso 1 6 d S . P . .
C4 C 0.1844(10) 0.000000 0.000000 0.088(3) Uiso 1 4 d S . P . .
C3 C 0.000000 0.000000 0.685(5) 0.107(6) Uiso 1 6 d S . P . .


_geom_special_details            
;
 All esds (except the esd in the dihedral angle between two l.s. planes)
 are estimated using the full covariance matrix.  The cell esds are taken
 into account individually in the estimation of esds in distances, angles
 and torsion angles; correlations between esds in cell parameters are only
 used when they are defined by crystal symmetry.  An approximate (isotropic)
 treatment of cell esds is used for estimating esds involving l.s. planes.
;
loop_
_axis.id
_axis.system
_axis.type
_axis.equipment
_axis.parity
_axis.depends_on
_axis.zero
_axis.vector[1]
_axis.vector[2]
_axis.vector[3]
source abstract . source . . . 0.99988797 0.00000000 -0.01496808
omega abstract rotation goniometer -1 . 0.74380000 0.00000000 0.00000000
1.00000000
kappa abstract rotation goniometer -1 omega 0.00084000 -0.76604444 0.00000000
0.64278761
phi abstract rotation goniometer -1 kappa . 0.00000000 0.00000000 1.00000000
theta abstract rotation goniometer -1 . -0.88015000 0.00000000 0.00000000
1.00000000
matrixX abstract general general . phi . 1.00000000 0.00000000 0.00000000
matrixY abstract general general . phi . 0.00000000 1.00000000 0.00000000
matrixZ abstract general general . phi . 0.00000000 0.00000000 1.00000000
dacX abstract translation general . phi . 0.00000000 1.00000000 0.00000000
dacY abstract translation general . phi . -1.00000000 0.00000000 0.00000000
dacZ abstract translation general . phi . 0.00000000 0.00000000 1.00000000

_olex2_submission_special_instructions 'No special instructions were received'
_oxdiff_exptl_absorpt_empirical_details 
;
Empirical correction (ABSPACK) includes:
- Absorption correction using spherical harmonics
- Frame scaling
;
_oxdiff_exptl_absorpt_empirical_full_max 1.703
_oxdiff_exptl_absorpt_empirical_full_min 0.508

data_Exp1_p14_MHIIb
_database_code_depnum_ccdc_archive 'CCDC 2521398'
loop_
_audit_author_name
_audit_author_address
'Katarzyna Skrzynska'
;ESRF
France
;
_audit_update_record             
;
2026-01-09 deposited with the CCDC.	2026-01-09 downloaded from the CCDC.
;
# start Validation Reply Form
_vrf_GEOM001_Exp1_p14_MHIIb      
;
PROBLEM: _geom_bond_atom_site_label_1 is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_GEOM002_Exp1_p14_MHIIb      
;
PROBLEM: _geom_bond_atom_site_label_2 is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_GEOM003_Exp1_p14_MHIIb      
;
PROBLEM: _geom_bond_distance is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_GEOM006_Exp1_p14_MHIIb      
;
PROBLEM: _geom_angle_atom_site_label_2 is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_GEOM007_Exp1_p14_MHIIb      
;
PROBLEM: _geom_angle_atom_site_label_3 is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_GEOM008_Exp1_p14_MHIIb      
;
PROBLEM: _geom_angle is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_PLAT029_Exp1_p14_MHIIb      
;
PROBLEM: _diffrn_measured_fraction_theta_full value Low .      0.482 Why?
RESPONSE: The low data completeness is due to the physical restrictions of the Diamond Anvil Cell and specific crystal orientation regarding to the beam.
;
_vrf_PLAT049_Exp1_p14_MHIIb      
;
PROBLEM: Calculated Density Less Than 1.0 gcm-3 .........     0.9536 Check
RESPONSE: The structure consists of an open, porous water framework containing cages populated by methane molecules, resulting in a lower density compared to compact ice phases.
;
# Added during the CSD deposition process: Friday 09 January 2026 09:17 AM
# end Validation Reply Form

_audit_creation_date             2025-05-16
_audit_creation_method           
;
Olex2 1.5
(compiled 2025.04.05 svn.rf049d14d for OlexSys, GUI svn.r7224)
;
_shelx_SHELXL_version_number     2019/3
_audit_contact_author_address    ?
_audit_contact_author_email      ?
_audit_contact_author_phone      ?
_publ_contact_author_id_orcid    ?
_publ_section_references         
;
Dolomanov, O.V., Bourhis, L.J., Gildea, R.J, Howard, J.A.K. & Puschmann, H.
 (2009), J. Appl. Cryst. 42, 339-341.

Sheldrick, G.M. (2015). Acta Cryst. C71, 3-8.
;
_chemical_name_common            ?
_chemical_name_systematic        'methane clathrate hydrate'
_chemical_formula_moiety         '34(O), 10(C)'
_chemical_formula_sum            'C10 O34'
_chemical_formula_weight         664.10
_chemical_absolute_configuration ?
_chemical_melting_point          ?
loop_
_atom_type_symbol
_atom_type_description
_atom_type_scat_dispersion_real
_atom_type_scat_dispersion_imag
_atom_type_scat_source
O O 0.0106 0.0060 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
C C 0.0033 0.0016 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'

_shelx_space_group_comment       
;
The symmetry employed for this shelxl refinement is uniquely defined
by the following loop, which should always be used as a source of
symmetry information in preference to the above space-group names.
They are only intended as comments.
;
_space_group_crystal_system      hexagonal
_space_group_IT_number           189
_space_group_name_H-M_alt        'P -6 2 m'
_space_group_name_Hall           'P -6 -2'
loop_
_space_group_symop_operation_xyz
'x, y, z'
'-y, x-y, z'
'-x+y, -x, z'
'x, y, -z'
'-y, x-y, -z'
'-x+y, -x, -z'
'y, x, -z'
'x-y, -y, -z'
'-x, -x+y, -z'
'y, x, z'
'x-y, -y, z'
'-x, -x+y, z'

_cell_length_a                   11.6508(6)
_cell_length_b                   11.6508(6)
_cell_length_c                   9.837(5)
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                120
_cell_volume                     1156.4(6)
_cell_formula_units_Z            1
_cell_measurement_reflns_used    632
_cell_measurement_temperature    296.15
_cell_measurement_pressure       2080000(20000)
_cell_measurement_theta_max      20.3260
_cell_measurement_theta_min      1.8340
_shelx_estimated_absorpt_T_max   0.990
_shelx_estimated_absorpt_T_min   0.990
_exptl_absorpt_coefficient_mu    0.106
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.25263
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   
;
CrysAlisPro 1.171.43.125a (Rigaku Oxford Diffraction, 2024)
Empirical absorption correction using spherical harmonics,
implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_absorpt_special_details   ?
_exptl_crystal_colour            ?
_exptl_crystal_density_diffrn    0.954
_exptl_crystal_density_meas      ?
_exptl_crystal_density_method    ?
_exptl_crystal_description       plate
_exptl_crystal_F_000             332
_exptl_crystal_size_max          0.04
_exptl_crystal_size_mid          0.04
_exptl_crystal_size_min          0.03
_exptl_transmission_factor_max   ?
_exptl_transmission_factor_min   ?
_diffrn_reflns_av_R_equivalents  0.0318
_diffrn_reflns_av_unetI/netI     0.0314
_diffrn_reflns_Laue_measured_fraction_full 0.482
_diffrn_reflns_Laue_measured_fraction_max 0.474
_diffrn_reflns_limit_h_max       15
_diffrn_reflns_limit_h_min       -15
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       -15
_diffrn_reflns_limit_l_max       5
_diffrn_reflns_limit_l_min       -5
_diffrn_reflns_number            2157
_diffrn_reflns_point_group_measured_fraction_full 0.488
_diffrn_reflns_point_group_measured_fraction_max 0.481
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         28.239
_diffrn_reflns_theta_min         4.541
_diffrn_ambient_temperature      296.15
_diffrn_detector                 'Hybrid Pixel Array Detector'
_diffrn_detector_area_resol_mean 13.3333
_diffrn_measured_fraction_theta_full 0.482
_diffrn_measured_fraction_theta_max 0.474
_diffrn_measurement_details      
;
List of Runs (angles in degrees, time in seconds):

  # Type    Start    End  Width  tₑₓₚ   ω     θ     κ     φ   Frames
#--------------------------------------------------------------------------
  1  ω    -32.00  30.00   0.50    2.00    --    0.00   0.00   0.00  124
;
_diffrn_measurement_device       'abstract diffractometer'
_diffrn_measurement_device_type  
'esperanto-CrysAlisPro-abstract goniometer imported esperanto images'
_diffrn_measurement_method       'ω scans'
_diffrn_orient_matrix_axis[1]    matrixX
_diffrn_orient_matrix_axis[2]    matrixY
_diffrn_orient_matrix_axis[3]    matrixZ
_diffrn_orient_matrix_type       
'CrysAlisPro convention (1999,Acta A55,543-557)'
_diffrn_orient_matrix_UB_11      0.0047950000
_diffrn_orient_matrix_UB_12      -0.0003305000
_diffrn_orient_matrix_UB_13      -0.0376526000
_diffrn_orient_matrix_UB_21      0.0338473000
_diffrn_orient_matrix_UB_22      0.0049321000
_diffrn_orient_matrix_UB_23      0.0057733000
_diffrn_orient_matrix_UB_31      -0.0141230000
_diffrn_orient_matrix_UB_32      -0.0366474000
_diffrn_orient_matrix_UB_33      0.0010363000
_diffrn_radiation_monochromator  synchrotron
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           synchrotron
_diffrn_radiation_wavelength     0.71075
_diffrn_source                   synchrotron
_reflns_Friedel_coverage         0.784
_reflns_Friedel_fraction_full    0.496
_reflns_Friedel_fraction_max     0.490
_reflns_number_gt                433
_reflns_number_total             528
_reflns_special_details          
;
 Reflections were merged by SHELXL according to the crystal
 class for the calculation of statistics and refinement.
 
 _reflns_Friedel_fraction is defined as the number of unique
 Friedel pairs measured divided by the number that would be
 possible theoretically, ignoring centric projections and
 systematic absences.
;
_reflns_threshold_expression     'I > 2σ(I)'
_computing_cell_refinement       'CrysAlisPro 1.171.43.125a (Rigaku OD, 2024)'
_computing_data_collection       
'CrysAlisPro 1.171.43.125a (Rigaku OD, 2024) (IMPORT)'
_computing_data_reduction        'CrysAlisPro 1.171.43.125a (Rigaku OD, 2024)'
_computing_molecular_graphics    'Olex2 1.5 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 1.5 (Dolomanov et al., 2009)'
_computing_structure_refinement  'SHELXL 2019/3 (Sheldrick, 2015)'
_computing_structure_solution    'SHELXT 2014/5 (Sheldrick, 2014)'
_refine_diff_density_max         0.262
_refine_diff_density_min         -0.222
_refine_diff_density_rms         0.065
_refine_ls_abs_structure_details 
;
 Flack x determined using 173 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   5.0(10)
_refine_ls_extinction_coef       .
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.062
_refine_ls_hydrogen_treatment    undef
_refine_ls_matrix_type           full
_refine_ls_number_parameters     38
_refine_ls_number_reflns         528
_refine_ls_number_restraints     0
_refine_ls_R_factor_all          0.0761
_refine_ls_R_factor_gt           0.0668
_refine_ls_restrained_S_all      1.062
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details     
'w=1/[σ²(Fo²)+(0.1438P)²] where P=(Fo²+2Fc²)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1768
_refine_ls_wR_factor_ref         0.1871
_refine_special_details          ?
_olex2_refinement_description    
;
;
_atom_sites_solution_hydrogens   .
_atom_sites_solution_primary     ?
_atom_sites_solution_secondary   ?
loop_
_atom_site_label
_atom_site_type_symbol
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_U_iso_or_equiv
_atom_site_adp_type
_atom_site_occupancy
_atom_site_site_symmetry_order
_atom_site_calc_flag
_atom_site_refinement_flags_posn
_atom_site_refinement_flags_adp
_atom_site_refinement_flags_occupancy
_atom_site_disorder_assembly
_atom_site_disorder_group
O1 O 0.1330(3) 0.2683(3) 0.500000 0.056(4) Uani 1 2 d S T P . .
O2 O 0.333333 0.666667 0.3677(14) 0.057(4) Uani 1 3 d S T P . .
O3 O 0.1954(3) 0.4171(3) 0.2748(8) 0.060(3) Uani 1 1 d . . . . .
O4 O 0.6567(4) 0.000000 0.1370(10) 0.057(5) Uani 1 2 d S T P . .
O5 O 0.4264(4) 0.000000 0.1381(13) 0.060(4) Uani 1 2 d S T P . .
C1 C 0.5102(7) 0.000000 0.500000 0.057(2) Uiso 1 4 d S . P . .
C2 C 0.333333 0.666667 0.000000 0.079(4) Uiso 1 6 d S . P . .
C4 C 0.1842(10) 0.000000 0.000000 0.085(3) Uiso 1 4 d S . P . .
C3 C 0.000000 0.000000 0.686(5) 0.106(6) Uiso 1 6 d S . P . .


_geom_special_details            
;
 All esds (except the esd in the dihedral angle between two l.s. planes)
 are estimated using the full covariance matrix.  The cell esds are taken
 into account individually in the estimation of esds in distances, angles
 and torsion angles; correlations between esds in cell parameters are only
 used when they are defined by crystal symmetry.  An approximate (isotropic)
 treatment of cell esds is used for estimating esds involving l.s. planes.
;
loop_
_axis.id
_axis.system
_axis.type
_axis.equipment
_axis.parity
_axis.depends_on
_axis.zero
_axis.vector[1]
_axis.vector[2]
_axis.vector[3]
source abstract . source . . . 0.99988797 0.00000000 -0.01496808
omega abstract rotation goniometer -1 . 0.74380000 0.00000000 0.00000000
1.00000000
kappa abstract rotation goniometer -1 omega 0.00084000 -0.76604444 0.00000000
0.64278761
phi abstract rotation goniometer -1 kappa . 0.00000000 0.00000000 1.00000000
theta abstract rotation goniometer -1 . -0.88015000 0.00000000 0.00000000
1.00000000
matrixX abstract general general . phi . 1.00000000 0.00000000 0.00000000
matrixY abstract general general . phi . 0.00000000 1.00000000 0.00000000
matrixZ abstract general general . phi . 0.00000000 0.00000000 1.00000000
dacX abstract translation general . phi . 0.00000000 1.00000000 0.00000000
dacY abstract translation general . phi . -1.00000000 0.00000000 0.00000000
dacZ abstract translation general . phi . 0.00000000 0.00000000 1.00000000

_olex2_submission_special_instructions 'No special instructions were received'
_oxdiff_exptl_absorpt_empirical_details 
;
Empirical correction (ABSPACK) includes:
- Absorption correction using spherical harmonics
- Frame scaling
;
_oxdiff_exptl_absorpt_empirical_full_max 1.921
_oxdiff_exptl_absorpt_empirical_full_min 0.479

data_Exp1_p15_MHIIb
_database_code_depnum_ccdc_archive 'CCDC 2521399'
loop_
_audit_author_name
_audit_author_address
'Katarzyna Skrzynska'
;ESRF
France
;
_audit_update_record             
;
2026-01-09 deposited with the CCDC.	2026-01-09 downloaded from the CCDC.
;
# start Validation Reply Form
_vrf_GEOM001_Exp1_p15_MHIIb      
;
PROBLEM: _geom_bond_atom_site_label_1 is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_GEOM002_Exp1_p15_MHIIb      
;
PROBLEM: _geom_bond_atom_site_label_2 is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_GEOM003_Exp1_p15_MHIIb      
;
PROBLEM: _geom_bond_distance is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_GEOM006_Exp1_p15_MHIIb      
;
PROBLEM: _geom_angle_atom_site_label_2 is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_GEOM007_Exp1_p15_MHIIb      
;
PROBLEM: _geom_angle_atom_site_label_3 is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_GEOM008_Exp1_p15_MHIIb      
;
PROBLEM: _geom_angle is missing
RESPONSE: The structure consists of water and methane molecules held together by hydrogen bonds and van der Waals interactions. There are no classical covalent bonds defined in this structure, therefore the geometry bond list is not applicable.
;
_vrf_PLAT029_Exp1_p15_MHIIb      
;
PROBLEM: _diffrn_measured_fraction_theta_full value Low .      0.483 Why?
RESPONSE: The low data completeness is due to the physical restrictions of the Diamond Anvil Cell and specific crystal orientation regarding to the beam.
;
_vrf_PLAT049_Exp1_p15_MHIIb      
;
PROBLEM: Calculated Density Less Than 1.0 gcm-3 .........     0.9588 Check
RESPONSE: The structure consists of an open, porous water framework containing cages populated by methane molecules, resulting in a lower density compared to compact ice phases.
;
# Added during the CSD deposition process: Friday 09 January 2026 09:20 AM
# end Validation Reply Form

_audit_creation_date             2025-05-16
_audit_creation_method           
;
Olex2 1.5
(compiled 2025.04.05 svn.rf049d14d for OlexSys, GUI svn.r7224)
;
_shelx_SHELXL_version_number     2019/3
_audit_contact_author_address    ?
_audit_contact_author_email      ?
_audit_contact_author_phone      ?
_publ_contact_author_id_orcid    ?
_publ_section_references         
;
Dolomanov, O.V., Bourhis, L.J., Gildea, R.J, Howard, J.A.K. & Puschmann, H.
 (2009), J. Appl. Cryst. 42, 339-341.

Sheldrick, G.M. (2015). Acta Cryst. C71, 3-8.
;
_chemical_name_common            ?
_chemical_name_systematic        'methane clathrate hydrate'
_chemical_formula_moiety         '34(O), 10(C)'
_chemical_formula_sum            'C10 O34'
_chemical_formula_weight         664.10
_chemical_absolute_configuration ?
_chemical_melting_point          ?
loop_
_atom_type_symbol
_atom_type_description
_atom_type_scat_dispersion_real
_atom_type_scat_dispersion_imag
_atom_type_scat_source
O O 0.0106 0.0060 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
C C 0.0033 0.0016 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'

_shelx_space_group_comment       
;
The symmetry employed for this shelxl refinement is uniquely defined
by the following loop, which should always be used as a source of
symmetry information in preference to the above space-group names.
They are only intended as comments.
;
_space_group_crystal_system      hexagonal
_space_group_IT_number           189
_space_group_name_H-M_alt        'P -6 2 m'
_space_group_name_Hall           'P -6 -2'
loop_
_space_group_symop_operation_xyz
'x, y, z'
'-y, x-y, z'
'-x+y, -x, z'
'x, y, -z'
'-y, x-y, -z'
'-x+y, -x, -z'
'y, x, -z'
'x-y, -y, -z'
'-x, -x+y, -z'
'y, x, z'
'x-y, -y, z'
'-x, -x+y, z'

_cell_length_a                   11.6203(10)
_cell_length_b                   11.6203(10)
_cell_length_c                   9.836(8)
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                120
_cell_volume                     1150.2(9)
_cell_formula_units_Z            1
_cell_measurement_reflns_used    567
_cell_measurement_temperature    296.15
_cell_measurement_pressure       2080000(20000)
_cell_measurement_theta_max      20.4210
_cell_measurement_theta_min      1.8350
_shelx_estimated_absorpt_T_max   0.989
_shelx_estimated_absorpt_T_min   0.989
_exptl_absorpt_coefficient_mu    0.106
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.14862
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   
;
CrysAlisPro 1.171.43.125a (Rigaku Oxford Diffraction, 2024)
Empirical absorption correction using spherical harmonics,
implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_absorpt_special_details   ?
_exptl_crystal_colour            ?
_exptl_crystal_density_diffrn    0.959
_exptl_crystal_density_meas      ?
_exptl_crystal_density_method    ?
_exptl_crystal_description       plate
_exptl_crystal_F_000             332
_exptl_crystal_size_max          0.04
_exptl_crystal_size_mid          0.04
_exptl_crystal_size_min          0.03
_exptl_transmission_factor_max   ?
_exptl_transmission_factor_min   ?
_diffrn_reflns_av_R_equivalents  0.0343
_diffrn_reflns_av_unetI/netI     0.0380
_diffrn_reflns_Laue_measured_fraction_full 0.483
_diffrn_reflns_Laue_measured_fraction_max 0.474
_diffrn_reflns_limit_h_max       15
_diffrn_reflns_limit_h_min       -15
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       -15
_diffrn_reflns_limit_l_max       5
_diffrn_reflns_limit_l_min       -5
_diffrn_reflns_number            2110
_diffrn_reflns_point_group_measured_fraction_full 0.486
_diffrn_reflns_point_group_measured_fraction_max 0.479
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         28.258
_diffrn_reflns_theta_min         4.550
_diffrn_ambient_temperature      296.15
_diffrn_detector                 'Hybrid Pixel Array Detector'
_diffrn_detector_area_resol_mean 13.3333
_diffrn_measured_fraction_theta_full 0.483
_diffrn_measured_fraction_theta_max 0.474
_diffrn_measurement_details      
;
List of Runs (angles in degrees, time in seconds):

  # Type    Start    End  Width  tₑₓₚ   ω     θ     κ     φ   Frames
#--------------------------------------------------------------------------
  1  ω    -32.00  30.00   0.50    2.00    --    0.00   0.00   0.00  124
;
_diffrn_measurement_device       'abstract diffractometer'
_diffrn_measurement_device_type  
'esperanto-CrysAlisPro-abstract goniometer imported esperanto images'
_diffrn_measurement_method       'ω scans'
_diffrn_orient_matrix_axis[1]    matrixX
_diffrn_orient_matrix_axis[2]    matrixY
_diffrn_orient_matrix_axis[3]    matrixZ
_diffrn_orient_matrix_type       
'CrysAlisPro convention (1999,Acta A55,543-557)'
_diffrn_orient_matrix_UB_11      0.0052812000
_diffrn_orient_matrix_UB_12      0.0047534000
_diffrn_orient_matrix_UB_13      -0.0377390000
_diffrn_orient_matrix_UB_21      0.0289538000
_diffrn_orient_matrix_UB_22      0.0338324000
_diffrn_orient_matrix_UB_23      0.0057973000
_diffrn_orient_matrix_UB_31      0.0225133000
_diffrn_orient_matrix_UB_32      -0.0142398000
_diffrn_orient_matrix_UB_33      0.0011679000
_diffrn_radiation_monochromator  synchrotron
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           synchrotron
_diffrn_radiation_wavelength     0.71075
_diffrn_source                   synchrotron
_reflns_Friedel_coverage         0.776
_reflns_Friedel_fraction_full    0.491
_reflns_Friedel_fraction_max     0.485
_reflns_number_gt                411
_reflns_number_total             524
_reflns_special_details          
;
 Reflections were merged by SHELXL according to the crystal
 class for the calculation of statistics and refinement.
 
 _reflns_Friedel_fraction is defined as the number of unique
 Friedel pairs measured divided by the number that would be
 possible theoretically, ignoring centric projections and
 systematic absences.
;
_reflns_threshold_expression     'I > 2σ(I)'
_computing_cell_refinement       'CrysAlisPro 1.171.43.125a (Rigaku OD, 2024)'
_computing_data_collection       
'CrysAlisPro 1.171.43.125a (Rigaku OD, 2024) (IMPORT)'
_computing_data_reduction        'CrysAlisPro 1.171.43.125a (Rigaku OD, 2024)'
_computing_molecular_graphics    'Olex2 1.5 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 1.5 (Dolomanov et al., 2009)'
_computing_structure_refinement  'SHELXL 2019/3 (Sheldrick, 2015)'
_computing_structure_solution    'SHELXT 2014/5 (Sheldrick, 2014)'
_refine_diff_density_max         0.248
_refine_diff_density_min         -0.232
_refine_diff_density_rms         0.064
_refine_ls_abs_structure_details 
;
 Flack x determined using 151 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   -3.7(10)
_refine_ls_extinction_coef       .
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.051
_refine_ls_hydrogen_treatment    undef
_refine_ls_matrix_type           full
_refine_ls_number_parameters     38
_refine_ls_number_reflns         524
_refine_ls_number_restraints     0
_refine_ls_R_factor_all          0.0828
_refine_ls_R_factor_gt           0.0701
_refine_ls_restrained_S_all      1.051
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details     
'w=1/[σ²(Fo²)+(0.1369P)²] where P=(Fo²+2Fc²)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1755
_refine_ls_wR_factor_ref         0.1887
_refine_special_details          ?
_olex2_refinement_description    
;
;
_atom_sites_solution_hydrogens   .
_atom_sites_solution_primary     ?
_atom_sites_solution_secondary   ?
loop_
_atom_site_label
_atom_site_type_symbol
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_U_iso_or_equiv
_atom_site_adp_type
_atom_site_occupancy
_atom_site_site_symmetry_order
_atom_site_calc_flag
_atom_site_refinement_flags_posn
_atom_site_refinement_flags_adp
_atom_site_refinement_flags_occupancy
_atom_site_disorder_assembly
_atom_site_disorder_group
O1 O 0.1334(3) 0.2685(4) 0.500000 0.058(4) Uani 1 2 d S T P . .
O2 O 0.333333 0.666667 0.3663(14) 0.053(5) Uani 1 3 d S T P . .
O3 O 0.1949(3) 0.4170(3) 0.2755(8) 0.063(4) Uani 1 1 d . . . . .
O4 O 0.6575(4) 0.000000 0.1378(11) 0.061(5) Uani 1 2 d S T P . .
O5 O 0.4266(4) 0.000000 0.1393(13) 0.060(5) Uani 1 2 d S T P . .
C1 C 0.5106(7) 0.000000 0.500000 0.058(2) Uiso 1 4 d S . P . .
C2 C 0.333333 0.666667 0.000000 0.086(4) Uiso 1 6 d S . P . .
C4 C 0.1834(11) 0.000000 0.000000 0.089(4) Uiso 1 4 d S . P . .
C3 C 0.000000 0.000000 0.689(6) 0.108(6) Uiso 1 6 d S . P . .


_geom_special_details            
;
 All esds (except the esd in the dihedral angle between two l.s. planes)
 are estimated using the full covariance matrix.  The cell esds are taken
 into account individually in the estimation of esds in distances, angles
 and torsion angles; correlations between esds in cell parameters are only
 used when they are defined by crystal symmetry.  An approximate (isotropic)
 treatment of cell esds is used for estimating esds involving l.s. planes.
;
loop_
_axis.id
_axis.system
_axis.type
_axis.equipment
_axis.parity
_axis.depends_on
_axis.zero
_axis.vector[1]
_axis.vector[2]
_axis.vector[3]
source abstract . source . . . 0.99988797 0.00000000 -0.01496808
omega abstract rotation goniometer -1 . 0.74380000 0.00000000 0.00000000
1.00000000
kappa abstract rotation goniometer -1 omega 0.00084000 -0.76604444 0.00000000
0.64278761
phi abstract rotation goniometer -1 kappa . 0.00000000 0.00000000 1.00000000
theta abstract rotation goniometer -1 . -0.88015000 0.00000000 0.00000000
1.00000000
matrixX abstract general general . phi . 1.00000000 0.00000000 0.00000000
matrixY abstract general general . phi . 0.00000000 1.00000000 0.00000000
matrixZ abstract general general . phi . 0.00000000 0.00000000 1.00000000
dacX abstract translation general . phi . 0.00000000 1.00000000 0.00000000
dacY abstract translation general . phi . -1.00000000 0.00000000 0.00000000
dacZ abstract translation general . phi . 0.00000000 0.00000000 1.00000000

_olex2_submission_special_instructions 'No special instructions were received'
_oxdiff_exptl_absorpt_empirical_details 
;
Empirical correction (ABSPACK) includes:
- Absorption correction using spherical harmonics
- Frame scaling
;
_oxdiff_exptl_absorpt_empirical_full_max 2.850
_oxdiff_exptl_absorpt_empirical_full_min 0.457
