data_global _chemical_name_mineral 'Heklaite' loop_ _publ_author_name 'Fischer J' 'Kramer V' _journal_name_full 'Materials Research Bulletin' _journal_volume 26 _journal_year 1991 _journal_page_first 925 _journal_page_last 930 _publ_section_title ; Crystal structure of KNaSiF_6_ ; _database_code_amcsd 0014361 _chemical_compound_source 'Synthetic' _chemical_formula_sum 'K Na Si F6' _cell_length_a 9.3246 _cell_length_b 5.4992 _cell_length_c 9.7892 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 501.969 _exptl_crystal_density_diffrn 2.702 _symmetry_space_group_name_H-M 'P n m a' loop_ _space_group_symop_operation_xyz 'x,y,z' 'x,1/2-y,z' '-x,1/2+y,-z' '1/2-x,1/2+y,1/2+z' '1/2+x,1/2-y,1/2-z' '1/2+x,y,1/2-z' '1/2-x,-y,1/2+z' '-x,-y,-z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z K 0.51360 0.25000 0.17980 Na 0.37180 0.25000 0.55960 Si 0.22900 0.25000 0.92060 F1 0.32740 0.46600 0.99410 F2 0.12540 0.03670 0.85480 F3 0.12440 0.25000 0.06010 F4 0.33130 0.25000 0.78430 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 K 0.03160 0.02770 0.02160 0.00000 0.00280 0.00000 Na 0.03640 0.02320 0.02790 0.00000 0.00250 0.00000 Si 0.01920 0.01620 0.01910 0.00000 0.00090 0.00000 F1 0.06600 0.03500 0.05270 -0.02180 -0.02190 0.00200 F2 0.08920 0.05430 0.06580 -0.03640 -0.03810 -0.00160 F3 0.04800 0.12520 0.04260 0.00000 0.02600 0.00000 F4 0.06900 0.11620 0.03420 0.00000 0.02610 0.00000