data_global _chemical_name_mineral 'Fluoro-richterite' loop_ _publ_author_name 'Cameron M' 'Sueno S' 'Papike J J' 'Prewitt C T' _journal_name_full 'American Mineralogist' _journal_volume 68 _journal_year 1983 _journal_page_first 924 _journal_page_last 943 _publ_section_title ; High temperature crystal chemistry of K and Na fluor-richterites Note: sample Na, T = 900 C ; _database_code_amcsd 0000916 _chemical_formula_sum 'Si8 Mg5 (Na2 Ca2) K4 O22 F2' _cell_length_a 10.043 _cell_length_b 18.149 _cell_length_c 5.286 _cell_angle_alpha 90 _cell_angle_beta 106.69 _cell_angle_gamma 90 _cell_volume 922.892 _exptl_crystal_density_diffrn 3.666 _symmetry_space_group_name_H-M 'I 1 2/m 1' loop_ _space_group_symop_operation_xyz 'x,y,z' '1/2+x,1/2+y,1/2+z' 'x,-y,z' '1/2+x,1/2-y,1/2+z' '-x,y,-z' '1/2-x,1/2+y,1/2-z' '-x,-y,-z' '1/2-x,1/2-y,1/2-z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z Si1 0.27940 0.91619 0.98572 Si2 0.28701 0.82988 0.48744 Mg1 0.00000 0.91042 0.50000 Mg2 0.00000 0.81940 0.00000 Mg3 0.00000 0.00000 0.00000 Na 0.00000 0.72346 0.50000 Ca 0.00000 0.72346 0.50000 K 0.46710 0.98872 0.55255 O1 0.11289 0.91517 0.89542 O2 0.11957 0.83203 0.39191 F3 0.10290 0.00000 0.39234 O4 0.36251 0.75333 0.56502 O5 0.34618 0.87246 0.26234 O6 0.34215 0.88137 0.76024 O7 0.34025 0.00000 0.04179 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 Si1 0.01781 0.01811 0.01699 0.00095 0.00741 -0.00074 Si2 0.01967 0.02007 0.01647 0.00229 0.00780 0.00006 Mg1 0.02557 0.02435 0.01989 0.00000 0.00871 0.00000 Mg2 0.02596 0.02535 0.02282 0.00000 0.00812 0.00000 Mg3 0.02612 0.02188 0.02311 0.00000 0.01447 0.00000 Na 0.06097 0.03206 0.03283 0.00000 -0.00419 0.00000 Ca 0.06097 0.03206 0.03283 0.00000 -0.00419 0.00000 K 0.11881 0.14941 0.08222 -0.02455 -0.03210 -0.00328 O1 0.02210 0.02415 0.02085 -0.00033 0.01016 -0.00036 O2 0.02075 0.03109 0.02129 0.00155 0.00557 -0.00131 F3 0.03719 0.03009 0.03462 0.00000 0.00971 0.00000 O4 0.04148 0.02445 0.03436 0.01128 0.01552 0.00043 O5 0.02692 0.03863 0.02373 0.00126 0.00854 0.01171 O6 0.03148 0.03736 0.02332 0.00107 0.01103 -0.01026 O7 0.03144 0.01639 0.04486 0.00000 0.00670 0.00000