data_global _chemical_name_mineral 'Coesite' loop_ _publ_author_name 'Levien L' 'Prewitt C T' _journal_name_full 'American Mineralogist' _journal_volume 66 _journal_year 1981 _journal_page_first 324 _journal_page_last 333 _publ_section_title ; High-pressure crystal structure and compressibility of coesite P = 46.0 kbar ; _database_code_amcsd 0000821 _chemical_formula_sum 'Si O2' _cell_length_a 7.0042 _cell_length_b 12.246 _cell_length_c 7.1177 _cell_angle_alpha 90 _cell_angle_beta 120.7 _cell_angle_gamma 90 _cell_volume 524.948 _exptl_crystal_density_diffrn 3.041 _symmetry_space_group_name_H-M 'C 1 2/c 1' loop_ _space_group_symop_operation_xyz 'x,y,z' '1/2+x,1/2+y,z' 'x,-y,1/2+z' '1/2+x,1/2-y,1/2+z' '-x,y,1/2-z' '1/2-x,1/2+y,1/2-z' '-x,-y,-z' '1/2-x,1/2-y,-z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_U_iso_or_equiv Si1 0.13700 0.10980 0.07040 0.00481 Si2 0.50850 0.15760 0.54410 0.00443 O1 0.00000 0.00000 0.00000 0.01305 O2 0.50000 0.10910 0.75000 0.00811 O3 0.25430 0.12910 0.92840 0.00722 O4 0.31790 0.10060 0.32510 0.00937 O5 0.02640 0.21290 0.47190 0.01013