data_global _chemical_name_mineral 'Tschernichite' loop_ _publ_author_name 'Alberti A' 'Cruciani G' 'Galli E' 'Merlino S' 'Millini R' 'Quartieri S' 'Vezzalini G' 'Zanardi S' _journal_name_full 'Journal of Physical Chemistry' _journal_volume B106 _journal_year 2002 _journal_page_first 10277 _journal_page_last 10284 _publ_section_title ; Crystal structure of tetragonal and monoclinic polytypes of tschernichite, the natural counterpart of synthetic zeolite beta Locality: Mt. Adamson, Northern Victoria Land, Antarctica Sample: small crystal, tetragonal Note: Mg position adjusted to match reported bond lengths ; _chemical_formula_sum 'Na.08 Mg.08 K.11 Ca.89 (Si13.26 Al2.74) O40.34 H30' _cell_length_a 12.634 _cell_length_b 12.634 _cell_length_c 26.608 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 4247.114 _exptl_crystal_density_diffrn 1.823 _symmetry_space_group_name_H-M 'P 41 2 2' loop_ _symmetry_equiv_pos_as_xyz 'x,y,z' 'y,x,3/4-z' '-y,x,1/4+z' '-x,y,-z' '-x,-y,1/2+z' '-y,-x,1/4-z' 'y,-x,3/4+z' 'x,-y,1/2-z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_occupancy _atom_site_U_iso_or_equiv Na -0.29100 -0.30000 0.12300 0.04000 0.04000 Mg -0.29100 -0.30000 0.12300 0.04000 0.04000 K1 0.00000 -0.12300 0.00000 0.04000 0.11000 Ca1 0.00000 -0.12300 0.00000 0.32000 0.11000 K2 0.00000 0.44900 0.00000 0.03000 0.05000 Ca2 0.00000 0.44900 0.00000 0.25000 0.05000 K3 -0.50000 -0.31800 0.00000 0.04000 0.10000 Ca3 -0.50000 -0.31800 0.00000 0.32000 0.10000 Si1 0.45790 0.29450 0.05620 0.70000 0.02000 Al1 0.45790 0.29450 0.05620 0.30000 0.02000 Si2 0.45730 0.04220 0.05410 0.90000 0.01800 Al2 0.45730 0.04220 0.05410 0.10000 0.01800 Si3 0.21110 0.29350 0.05650 0.85000 0.01600 Al3 0.21110 0.29350 0.05650 0.15000 0.01600 Si4 0.21130 0.04190 0.05750 0.83000 0.01700 Al4 0.21130 0.04190 0.05750 0.17000 0.01700 Si5 0.83600 0.29380 0.05660 0.99000 0.01900 Al5 0.83600 0.29380 0.05660 0.01000 0.01900 Si6 0.83550 0.04110 0.05770 0.76000 0.01800 Al6 0.83550 0.04110 0.05770 0.24000 0.01800 Si7 0.02710 0.35830 0.12510 0.78000 0.02100 Al7 0.02710 0.35830 0.12510 0.22000 0.02100 Si8 0.02620 -0.02620 0.12500 0.71000 0.01600 Al8 0.02620 -0.02620 0.12500 0.29000 0.01600 Si9 0.64030 0.35970 0.12500 0.93000 0.01900 Al9 0.64030 0.35970 0.12500 0.07000 0.01900 O1 0.50000 0.33950 0.00000 1.00000 0.02300 O2 0.46910 0.16390 0.06080 1.00000 0.03500 O3 0.33630 0.33100 0.06310 1.00000 0.03900 O4 0.52670 0.35420 0.09940 1.00000 0.03700 O5 0.50000 0.08000 0.00000 1.00000 0.03000 O6 0.33400 0.00180 0.06260 1.00000 0.03700 O7 0.52270 -0.01800 0.09930 1.00000 0.03300 O8 0.20170 0.16790 0.06610 1.00000 0.04700 O9 0.16430 0.32240 0.00180 1.00000 0.02800 O10 0.14680 0.35390 0.10040 1.00000 0.03600 O11 0.16410 0.00560 0.00240 1.00000 0.03900 O12 0.14580 -0.02080 0.09980 1.00000 0.03300 O13 0.83480 0.16960 0.06390 1.00000 0.05000 O14 0.93740 0.34800 0.08090 1.00000 0.03600 O15 0.72980 0.34810 0.08280 1.00000 0.05700 O16 0.72960 -0.01630 0.08220 1.00000 0.03500 O17 0.94120 -0.00940 0.07890 1.00000 0.05000 Wat1 -0.18600 -0.22900 0.05700 0.55000 0.09000 Wat2 -0.16700 -0.41600 0.05600 0.93000 0.22000 Wat3 0.00000 0.54600 0.00000 0.38000 0.10000 Wat4 -0.35900 -0.20600 0.00500 0.86000 0.19000 Wat6 -0.46300 -0.32300 0.09000 0.67000 0.18000 Wat7 -0.36100 -0.47800 0.00600 0.31000 0.11000 Wat10 -0.15500 -0.34600 -0.00200 0.30000 0.06000 Wat11 -0.33400 -0.33400 -0.12500 0.34000 0.08000 Wat13 0.00000 -0.20300 0.00000 0.38000 0.05000