data_global _chemical_name_mineral 'Cristobalite' loop_ _publ_author_name 'Downs R T' 'Palmer D C' _journal_name_full 'American Mineralogist' _journal_volume 79 _journal_year 1994 _journal_page_first 9 _journal_page_last 14 _publ_section_title ; The pressure behavior of alpha cristobalite P = 0.73 GPa ; _database_code_amcsd 0001631 _chemical_compound_source 'Ellora Caves, India' _chemical_formula_sum 'Si O2' _cell_length_a 4.9028 _cell_length_b 4.9028 _cell_length_c 6.7782 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 162.931 _exptl_crystal_density_diffrn 2.449 _symmetry_space_group_name_H-M 'P 41 21 2' loop_ _space_group_symop_operation_xyz 'x,y,z' 'y,x,-z' '1/2-y,1/2+x,1/4+z' '1/2-x,1/2+y,1/4-z' '-x,-y,1/2+z' '-y,-x,1/2-z' '1/2+y,1/2-x,3/4+z' '1/2+x,1/2-y,3/4-z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_U_iso_or_equiv Si 0.30860 0.30860 0.00000 0.00798 O 0.23640 0.11980 0.18700 0.01355