data_global _chemical_name_mineral 'Cristobalite low' loop_ _publ_author_name 'Nieuwenkamp W' _journal_name_full 'Zeitschrift fur Kristallographie' _journal_volume 92 _journal_year 1935 _journal_page_first 82 _journal_page_last 88 _publ_section_title ; Die Kristallstruktur des Tief-Cristobalits Si O2 _cod_database_code 1010938 ; _database_code_amcsd 0017659 _chemical_formula_sum 'Si O2' _cell_length_a 4.964 _cell_length_b 4.964 _cell_length_c 6.920 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 170.518 _exptl_crystal_density_diffrn 2.340 _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 Si1 0.30000 0.30000 0.00000 O1 0.24500 0.10000 0.17500