data_global _chemical_name_mineral 'Boromuscovite' loop_ _publ_author_name 'Liang J' 'Hawthorne F C' 'Novak M' 'Cerny P' _journal_name_full 'The Canadian Mineralogist' _journal_volume 33 _journal_year 1995 _journal_page_first 859 _journal_page_last 865 _publ_section_title ; Crystal-structure refinement of boromuscovite polytypes using a coupled Rietveld-static-structure energy-minimization method Sample: 2M1 polytype ; _database_code_amcsd 0005445 _chemical_compound_source 'Recice, Czech Republic' _chemical_formula_sum 'Al1.92 (Si3 B) K.41 O12' _cell_length_a 5.090 _cell_length_b 8.822 _cell_length_c 19.819 _cell_angle_alpha 90 _cell_angle_beta 95.62 _cell_angle_gamma 90 _cell_volume 885.674 _exptl_crystal_density_diffrn 2.662 _symmetry_space_group_name_H-M 'C 1 2/c 1' loop_ _space_group_symop_operation_xyz 'x,y,z' '1/2+x,1/2+y,z' 'x,-y,1/2+z' '1/2+x,1/2-y,1/2+z' '-x,y,1/2-z' '1/2-x,1/2+y,1/2-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 Al 0.25000 0.07900 -0.00020 0.96000 0.00595 SiT1 0.44200 0.25400 0.13510 0.78000 0.00152 BT1 0.44200 0.25400 0.13510 0.22000 0.00152 SiT2 0.04500 0.42600 0.36400 0.72000 0.00215 BT2 0.04500 0.42600 0.36400 0.28000 0.00215 K 0.00000 0.10300 0.25000 0.41000 0.00329 O 0.03900 0.07200 0.45410 1.00000 0.00443 O1 0.38500 0.24800 0.05690 1.00000 0.00469 O2 0.04300 0.43800 0.44660 1.00000 0.00367 O3 0.41900 0.09000 0.16550 1.00000 0.00481 O4 0.22900 0.36100 0.16360 1.00000 0.00861 O5 0.27000 0.31400 0.34660 1.00000 0.00405