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 = 31.5 kbar ; _database_code_amcsd 0000819 _chemical_formula_sum 'Si O2' _cell_length_a 7.0407 _cell_length_b 12.279 _cell_length_c 7.1342 _cell_angle_alpha 90 _cell_angle_beta 120.610 _cell_angle_gamma 90 _cell_volume 530.826 _exptl_crystal_density_diffrn 3.007 _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 0.13780 0.10930 0.07110 0.00557 Si2 0.50810 0.15760 0.54340 0.00545 O1 0.00000 0.00000 0.00000 0.01153 O2 0.50000 0.11070 0.75000 0.00874 O3 0.25760 0.12720 0.93200 0.00849 O4 0.31570 0.10200 0.32630 0.00963 O5 0.02340 0.21260 0.47280 0.01039