data_global _chemical_name_mineral 'Tridymite' loop_ _publ_author_name 'Graetsch H' 'Topalovic-Dierdorf I' _journal_name_full 'European Journal of Mineralogy' _journal_volume 8 _journal_year 1996 _journal_page_first 103 _journal_page_last 113 _publ_section_title ; 29Si MAS NMR spectrum and superstructure of modulated tridymite L3-To(MX-1) Sample: superstructure ; _database_code_amcsd 0006615 _chemical_compound_source 'Synthetic' _chemical_formula_sum 'Si O2' _cell_length_a 15.021 _cell_length_b 8.6004 _cell_length_c 16.4338 _cell_angle_alpha 90. _cell_angle_beta 91.512 _cell_angle_gamma 90. _cell_volume 2122.288 _exptl_crystal_density_diffrn 2.257 _symmetry_space_group_name_H-M 'C 1' loop_ _space_group_symop_operation_xyz 'x,y,z' '1/2+x,1/2+y,z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_U_iso_or_equiv Si1(1) 0.19240 0.11870 0.16400 1.02380 Si1(2) 0.53200 0.13630 0.18300 2.03040 Si1(3) 0.85240 0.14110 0.15000 4.02020 Si1(4) 0.18470 0.79070 0.08500 7.03030 Si1(5) 0.02860 0.30920 0.11200 2.03310 Si1(6) 0.36190 0.28850 0.11300 8.02880 Si2(1) 0.19400 0.16940 0.35200 1.02120 Si2(2) 0.20150 0.85120 0.43400 8.02110 Si2(3) 0.53310 0.18310 0.37000 9.01720 Si2(4) 0.02140 0.33650 0.40800 2.02910 Si2(5) 0.85220 0.19120 0.33800 6.02040 Si2(6) 0.35770 0.35760 0.40600 1.02750 Si3(1) 0.20220 0.80060 0.62100 9.02690 Si3(2) 0.02200 0.28800 0.59400 7.01860 Si3(3) 0.35910 0.30750 0.59300 5.02460 Si3(4) 0.19380 0.14420 0.66700 7.03000 Si3(5) 0.52360 0.12540 0.64900 9.02940 Si3(6) 0.86750 0.12410 0.68100 3.01950 Si4(1) 0.19190 0.19560 0.85400 0.03250 Si4(2) 0.18710 0.84210 0.89800 0.02680 Si4(3) 0.52050 0.17620 0.83800 1.02700 Si4(4) 0.02960 0.36340 0.92400 2.02980 Si4(5) 0.86790 0.17590 0.86800 8.02890 Si4(6) 0.36300 0.33880 0.92600 7.02290 O1(1) 0.26230 0.24560 0.13100 4.03410 O1(2) 0.59530 0.23420 0.12600 2.03660 O1(3) 0.92860 0.25440 0.11600 7.03480 O1(4) 0.21670 0.95180 0.12900 8.03430 O1(5) 0.26390 0.66850 0.09600 9.02680 O1(6) 0.04860 0.45430 0.17100 2.03170 O1(7) 0.09720 0.16930 0.13500 8.04890 O1(8) 0.38320 0.46270 0.14500 0.03570 O1(9) 0.43130 0.17730 0.15900 6.03230 O1/2(1) 0.19790 0.10280 0.26100 0.04760 O1/2(2) 0.55470 0.18320 0.27500 0.02610 O1/2(3) 0.83380 0.18460 0.24300 3.03540 O2(1) 0.21850 0.03130 0.41400 3.03390 O2(2) 0.26420 0.30580 0.36800 7.04780 O2(3) 0.26050 0.74630 0.38000 6.03610 O2(4) 0.54880 0.01480 0.40900 5.04430 O2(5) 0.59930 0.30210 0.41800 8.02030 O2(6) 0.09570 0.23890 0.36400 2.03390 O2(7) 0.88350 0.02420 0.37100 5.02740 O2(8) 0.92990 0.31770 0.36100 1.03570 O2(9) 0.43170 0.23290 0.38200 9.03390 O2/3(1) 0.22830 0.82290 0.52800 9.02700 O2/3(2) 0.01240 0.27380 0.49900 9.03640 O2/3(3) 0.34650 0.37560 0.50200 0.05090 O3(1) 0.21660 0.96030 0.67100 9.03510 O3(2) 0.26520 0.67280 0.66000 8.03230 O3(3) 0.05200 0.45660 0.62200 1.03230 O3(4) 0.09760 0.17030 0.62000 8.05300 O3(5) 0.38330 0.44660 0.65300 2.03940 O3(6) 0.43360 0.17790 0.60000 1.03890 O3(7) 0.26600 0.24130 0.61300 6.04020 O3(8) 0.59920 0.25190 0.62800 2.02570 O3(9) 0.92830 0.24570 0.63400 8.03000 O3/4(1) 0.19220 0.21050 0.75900 1.04320 O3/4(2) 0.50430 0.12710 0.74600 2.03870 O3/4(3) 0.88740 0.13020 0.77800 2.03070 O4(1) 0.21780 0.01940 0.88200 3.03860 O4(2) 0.26140 0.31020 0.89800 9.03590 O4(3) 0.26610 0.73110 0.87300 2.02930 O4(4) 0.55030 0.03230 0.89200 0.04390 O4(5) 0.59970 0.30320 0.84300 7.02080 O4(6) 0.09620 0.23810 0.88200 8.03490 O4(7) 0.88210 0.02480 0.92400 7.03220 O4(8) 0.92780 0.31480 0.90200 4.02760 O4(9) 0.42980 0.24520 0.87000 0.02830 O4/1(1) 0.16200 0.82450 -0.00900 8.03630 O4/1(2) 0.04470 0.36550 0.01900 5.03430 O4/1(3) 0.37770 0.28160 0.01700 0.04990