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 = 373 K ; _database_code_amcsd 0013133 _chemical_compound_source 'Synthetic' _chemical_formula_sum 'Si O2' _cell_length_a 25.919 _cell_length_b 5.004 _cell_length_c 18.540 _cell_angle_alpha 90 _cell_angle_beta 117.72 _cell_angle_gamma 90 _cell_volume 2128.639 _exptl_crystal_density_diffrn 2.250 _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 0.70130 0.03140 Si2 0.01120 0.20060 -0.03830 Si3 0.14690 0.21210 0.04590 Si4 0.18140 0.71320 -0.01510 Si5 0.30980 0.70840 0.01260 Si6 0.34810 0.21140 -0.04440 Si7 0.04200 0.79420 0.21930 Si8 0.11630 0.29500 0.29780 Si9 0.20610 0.30770 0.23290 Si10 0.28360 0.80560 0.27120 Si11 0.36870 0.70120 0.20160 Si12 0.44370 0.20100 0.27150 O1 -0.08380 0.75200 0.01160 O2 -0.00080 0.90300 -0.01990 O3 -0.01220 0.39800 0.00720 O4 0.07830 0.24900 -0.01050 O5 0.18000 0.41600 0.01590 O6 0.16570 -0.08800 0.03990 O7 0.24370 0.77400 -0.00740 O8 0.31250 0.41300 -0.01670 O9 0.32890 -0.08900 -0.03650 O10 0.02310 0.74500 0.12490 O11 0.16250 0.26700 0.13780 O12 0.35270 0.73800 0.10870 O13 -0.01330 0.74900 0.23260 O14 0.06510 0.09500 0.24230 O15 0.09390 0.59500 0.27510 O16 0.17230 0.24900 0.28530 O17 0.23040 0.60700 0.25020 O18 0.25950 0.10700 0.26060 O19 0.31140 0.75600 0.21200 O20 0.39020 0.40300 0.22990 O21 0.41970 0.90300 0.25580 O22 0.13380 0.24400 0.39140 O23 0.33390 0.76300 0.36290 O24 0.47690 0.25000 0.36580