data_global _chemical_name_mineral 'Methane-hydrate' loop_ _publ_author_name 'Kirchner M T' 'Boese R' 'Billups W E' 'Norman L R' _journal_name_full 'Journal of the American Chemical Society' _journal_volume 126 _journal_year 2004 _journal_page_first 9407 _journal_page_last 9412 _publ_section_title ; Gas hydrate single-crystal structure analyses Sample: (CH4)8(H2O)46, T = 123 K ; _database_code_amcsd 0019155 _chemical_compound_source 'Synthetic' _chemical_formula_sum 'O23 H61.96 C4' _cell_length_a 11.877 _cell_length_b 11.877 _cell_length_c 11.877 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 1675.407 _exptl_crystal_density_diffrn 0.948 _symmetry_space_group_name_H-M 'P m 3 n' loop_ _space_group_symop_operation_xyz 'x,y,z' 'z,-x,y' '-y,z,-x' 'x,-y,z' '-z,x,-y' 'y,-z,x' '-x,y,-z' '1/2+x,1/2-z,1/2-y' '1/2-z,1/2+y,1/2+x' '1/2+y,1/2-x,1/2-z' '1/2-x,1/2+z,1/2+y' '1/2+z,1/2-y,1/2-x' '1/2-y,1/2+x,1/2+z' '1/2+x,1/2+z,1/2+y' '1/2-z,1/2-y,1/2-x' '1/2+y,1/2+x,1/2+z' '1/2-x,1/2-z,1/2-y' '1/2+z,1/2+y,1/2+x' '1/2-y,1/2-x,1/2-z' 'z,x,-y' '-y,-z,x' 'x,y,-z' '-z,-x,y' 'y,z,-x' '-x,-y,z' '-z,x,y' 'y,-z,-x' '-x,y,z' 'z,-x,-y' '-y,z,x' 'x,-y,-z' '1/2-x,1/2+z,1/2-y' '1/2+z,1/2-y,1/2+x' '1/2-y,1/2+x,1/2-z' '1/2+x,1/2-z,1/2+y' '1/2-z,1/2+y,1/2-x' '1/2+y,1/2-x,1/2+z' '1/2-x,1/2-z,1/2+y' '1/2+z,1/2+y,1/2-x' '1/2-y,1/2-x,1/2+z' '1/2+x,1/2+z,1/2-y' '1/2-z,1/2-y,1/2+x' '1/2+y,1/2+x,1/2-z' '-z,-x,-y' 'y,z,x' '-x,-y,-z' 'z,x,y' '-y,-z,-x' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_occupancy _atom_site_U_iso_or_equiv O1 0.00000 0.30860 0.11683 1.00000 0.02910 H1 0.00000 0.32500 0.05100 0.50000 0.04400 H2 0.05100 0.27100 0.13400 0.50000 0.04400 H3 0.00000 0.36000 0.15000 0.50000 0.04400 O2 0.18345 0.18345 0.18345 1.00000 0.02860 H4 0.21600 0.21600 0.21600 0.50000 0.04300 H5 0.16200 0.12800 0.22000 0.50000 0.04300 O3 0.00000 0.50000 0.25000 1.00000 0.02920 H6 0.00000 0.44700 0.21100 0.50000 0.04400 C1 0.00000 0.00000 0.00000 1.00000 0.05180 H7 0.00000 0.04900 0.08600 0.33000 0.07800 C2 0.25000 0.50000 0.00000 1.00000 0.11300 H8 0.29860 0.50000 0.06870 0.50000 0.17000 H9 0.20140 0.50000 0.06870 0.50000 0.17000 loop_ _atom_site_aniso_label _atom_site_aniso_U_11 _atom_site_aniso_U_22 _atom_site_aniso_U_33 _atom_site_aniso_U_12 _atom_site_aniso_U_13 _atom_site_aniso_U_23 O1 0.03040 0.02870 0.02810 0.00000 0.00000 -0.00040 O2 0.02860 0.02860 0.02860 -0.00110 -0.00110 -0.00110 O3 0.02740 0.02740 0.03280 0.00000 0.00000 0.00000 C1 0.05180 0.05180 0.05180 0.00000 0.00000 0.00000 C2 0.08000 0.13000 0.13000 0.00000 0.00000 0.00000