data_global _chemical_name_mineral 'Tridymite' loop_ _publ_author_name 'Hirose T' 'Kihara K' 'Okuno M' 'Fujinami S' 'Shinoda K' _journal_name_full 'Journal of Mineralogical and Petrological Sciences' _journal_volume 100 _journal_year 2005 _journal_page_first 55 _journal_page_last 69 _publ_section_title ; X-ray, DTA and Raman studies of monoclinic tridymite and its higher temperature orthorhombic modification with varying temperature. Note: T = 298 K ; _database_code_amcsd 0013132 _chemical_compound_source 'Synthetic' _chemical_formula_sum 'Si O2' _cell_length_a 25.878 _cell_length_b 5.001 _cell_length_c 18.526 _cell_angle_alpha 90 _cell_angle_beta 117.69 _cell_angle_gamma 90 _cell_volume 2122.977 _exptl_crystal_density_diffrn 2.256 _symmetry_space_group_name_H-M 'A 1 a 1' loop_ _space_group_symop_operation_xyz 'x,y,z' 'x,1/2+y,1/2+z' '1/2+x,-y,z' '1/2+x,1/2-y,1/2+z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z Si1 -0.01790 0.69820 0.03140 Si2 0.01080 0.19790 -0.03930 Si3 0.14680 0.21120 0.04690 Si4 0.18120 0.71290 -0.01430 Si5 0.30910 0.70740 0.01110 Si6 0.34780 0.21060 -0.04520 Si7 0.04160 0.79630 0.21880 Si8 0.11580 0.29720 0.29890 Si9 0.20570 0.31010 0.23380 Si10 0.28320 0.80900 0.27030 Si11 0.36760 0.69950 0.20030 Si12 0.44250 0.19950 0.27040 O1 -0.08390 0.75100 0.01310 O2 -0.00110 0.89600 -0.02160 O3 -0.01290 0.39400 0.00740 O4 0.07810 0.24900 -0.01090 O5 0.18080 0.41300 0.01760 O6 0.16630 -0.08900 0.04190 O7 0.24370 0.77800 -0.00810 O8 0.31150 0.41000 -0.01820 O9 0.32870 -0.09100 -0.03830 O10 0.02400 0.74500 0.12580 O11 0.16030 0.26900 0.13800 O12 0.35180 0.73800 0.10710 O13 -0.01500 0.75000 0.23070 O14 0.06380 0.09800 0.24170 O15 0.09340 0.59700 0.27630 O16 0.17210 0.25100 0.28610 O17 0.22970 0.61300 0.25070 O18 0.25950 0.11100 0.26090 O19 0.30950 0.75700 0.20900 O20 0.38790 0.39800 0.22790 O21 0.41900 0.90100 0.25570 O22 0.13180 0.24200 0.39230 O23 0.33360 0.76600 0.36130 O24 0.47550 0.25200 0.36520