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 = 38.7 kbar ; _database_code_amcsd 0000820 _chemical_formula_sum 'Si O2' _cell_length_a 7.0213 _cell_length_b 12.260 _cell_length_c 7.1252 _cell_angle_alpha 90 _cell_angle_beta 120.66 _cell_angle_gamma 90 _cell_volume 527.605 _exptl_crystal_density_diffrn 3.026 _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 0.13740 0.10950 0.07070 0.00507 Si2 0.50850 0.15720 0.54390 0.00481 O1 0.00000 0.00000 0.00000 0.01140 O2 0.50000 0.10950 0.75000 0.00697 O3 0.25580 0.12790 0.93020 0.00785 O4 0.31670 0.10060 0.32570 0.00925 O5 0.02460 0.21350 0.47240 0.01001