data_global _chemical_name_mineral 'Preiswerkite' loop_ _publ_author_name 'Oberti R' 'Ungaretti L' 'Tlili A' 'Smith D C' 'Robert J-L' _journal_name_full 'American Mineralogist' _journal_volume 78 _journal_year 1993 _journal_page_first 1290 _journal_page_last 1298 _publ_section_title ; The crystal structure of preiswerkite Sample: KP9 ; _database_code_amcsd 0001620 _chemical_formula_sum 'Si2 Al3.15 Mg1.85 Na.85 O12 H2' _cell_length_a 5.225 _cell_length_b 9.050 _cell_length_c 9.791 _cell_angle_alpha 90 _cell_angle_beta 100.27 _cell_angle_gamma 90 _cell_volume 455.562 _exptl_crystal_density_diffrn 2.914 _symmetry_space_group_name_H-M 'C 1 2/m 1' loop_ _space_group_symop_operation_xyz 'x,y,z' '1/2+x,1/2+y,z' 'x,-y,z' '1/2+x,1/2-y,z' '-x,y,-z' '1/2-x,1/2+y,-z' '-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_occupancy _atom_site_U_iso_or_equiv SiT 0.57090 0.16660 0.21260 0.50000 ? AlT 0.57090 0.16660 0.21260 0.50000 ? Mg1 0.00000 0.50000 0.50000 0.85000 ? Al1 0.00000 0.50000 0.50000 0.15000 ? Mg2 0.00000 0.82910 0.50000 0.50000 ? Al2 0.00000 0.82910 0.50000 0.50000 ? Na 0.00000 0.00000 0.00000 0.85000 ? O1 0.85460 0.19710 0.15930 1.00000 ? O2 0.44870 0.00000 0.15980 1.00000 ? O3 0.62850 0.16850 0.39180 1.00000 ? O-h4 0.13350 0.00000 0.39700 1.00000 ? H 0.07490 0.00000 0.30420 1.00000 0.01267 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 SiT 0.00455 0.00664 0.00658 0.00000 0.00100 0.00000 AlT 0.00455 0.00664 0.00658 0.00000 0.00100 0.00000 Mg1 0.00429 0.00913 0.01176 0.00000 0.00151 0.00000 Al1 0.00429 0.00913 0.01176 0.00000 0.00151 0.00000 Mg2 0.00817 0.00664 0.00799 0.00000 0.00050 0.00000 Al2 0.00817 0.00664 0.00799 0.00000 0.00050 0.00000 Na 0.01433 0.01743 0.01505 0.00000 0.00351 0.00000 O1 0.00911 0.00373 0.01223 0.00283 0.00326 -0.00133 O2 0.00388 0.00415 0.01505 0.00000 0.00527 0.00000 O3 0.01486 0.00996 0.00799 0.00071 -0.00125 0.00353 O-h4 0.01634 0.02904 0.01081 0.00000 0.00301 0.00000