data_global _chemical_name_mineral 'Quartz' loop_ _publ_author_name 'Kihara K' _journal_name_full 'European Journal of Mineralogy' _journal_volume 2 _journal_year 1990 _journal_page_first 63 _journal_page_last 77 _publ_section_title ; An X-ray study of the temperature dependence of the quartz structure Sample: at T = 498 K ; _database_code_amcsd 0006364 _chemical_formula_sum 'Si O2' _cell_length_a 4.9297 _cell_length_b 4.9297 _cell_length_c 5.4151 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 120 _cell_volume 113.967 _exptl_crystal_density_diffrn 2.626 _symmetry_space_group_name_H-M 'P 32 2 1' loop_ _space_group_symop_operation_xyz 'x,y,z' 'y,x,2/3-z' '-y,x-y,2/3+z' '-x,-x+y,1/3-z' '-x+y,-x,1/3+z' 'x-y,-y,-z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z Si 0.47230 0.00000 0.00000 O 0.41410 0.26300 0.12240 loop_ _atom_site_aniso_label _atom_site_aniso_U_11 _atom_site_aniso_U_22 _atom_site_aniso_U_33 _atom_site_aniso_U_12 _atom_site_aniso_U_13 _atom_site_aniso_U_23 Si 0.01145 0.00905 0.00995 0.00452 -0.00018 -0.00035 O 0.02604 0.01921 0.01946 0.01496 -0.00457 -0.00796