Gas Hydrate Single-Crystal Structure Analyses
Michael T. Kirchner; Roland Boese; W. Edward Billups; Lewis R. Norman; Journal of the American Chemical Society 126 (2004) 9407–9412; doi:10.1021/ja049247c

data_4112809
_publ_section_title
;
 Gas Hydrate Single-Crystal Structure Analyses
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              9407
_journal_page_last               9412
_journal_paper_doi               10.1021/ja049247c
_journal_volume                  126
_journal_year                    2004
_chemical_compound_source        Synthetic
_chemical_formula_moiety         '8(C H4), 46(H2 O)'
_chemical_formula_sum            'C8 H124 O46'
_chemical_formula_weight         957.07
_chemical_name_common            'Methane hydrate'
_chemical_name_mineral           Methane-hydrate
_chemical_name_systematic
; 
 clathrate hydrate of methane
;
_space_group_IT_number           223
_symmetry_cell_setting           cubic
_symmetry_space_group_name_Hall  '-P 4n 2 3'
_symmetry_space_group_name_H-M   'P m -3 n'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            1
_cell_length_a                   11.877(3)
_cell_length_b                   11.877(3)
_cell_length_c                   11.877(3)
_cell_measurement_temperature    123(2)
_cell_volume                     1675.4(7)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_database_code_amcsd             0019155
_diffrn_ambient_temperature      123(2)
_diffrn_measured_fraction_theta_full 0.990
_diffrn_measured_fraction_theta_max 0.990
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0743
_diffrn_reflns_av_sigmaI/netI    0.0337
_diffrn_reflns_limit_h_max       15
_diffrn_reflns_limit_h_min       -15
_diffrn_reflns_limit_k_max       8
_diffrn_reflns_limit_k_min       -9
_diffrn_reflns_limit_l_max       15
_diffrn_reflns_limit_l_min       -12
_diffrn_reflns_number            5581
_diffrn_reflns_theta_full        28.23
_diffrn_reflns_theta_max         28.23
_diffrn_reflns_theta_min         3.84
_exptl_absorpt_coefficient_mu    0.099
_exptl_absorpt_correction_T_max  1
_exptl_absorpt_correction_T_min  0.885
_exptl_absorpt_correction_type   empirical
_exptl_absorpt_process_details   'Bruker AXS SADABS program multiscan V2.03'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    0.948
_exptl_crystal_F_000             540
_exptl_crystal_size_max          0.30
_exptl_crystal_size_mid          0.00
_exptl_crystal_size_min          0.00
_refine_diff_density_max         0.214
_refine_diff_density_min         -0.148
_refine_diff_density_rms         0.044
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.094
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     30
_refine_ls_number_reflns         399
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.094
_refine_ls_R_factor_all          0.0682
_refine_ls_R_factor_gt           0.0379
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0367P)^2^+0.1641P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0759
_refine_ls_wR_factor_ref         0.0887
_reflns_number_gt                268
_reflns_number_total             399
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja049247csi20040211_052221.cif
_cod_data_source_block           xdablt2a
_cod_original_cell_volume        1675.6(8)
_cod_database_code               4112809