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 K, T = 800 C ; _database_code_amcsd 0000920 _chemical_formula_sum 'Si8 Mg5 (Na2 Ca2) K2 O22 F2' _cell_length_a 10.104 _cell_length_b 18.159 _cell_length_c 5.285 _cell_angle_alpha 90 _cell_angle_beta 105.85 _cell_angle_gamma 90 _cell_volume 932.817 _exptl_crystal_density_diffrn 3.349 _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 0.27485 0.91572 0.97684 Si2 0.28475 0.82934 0.48051 Mg1 0.00000 0.90983 0.50000 Mg2 0.00000 0.81913 0.00000 Mg3 0.00000 0.00000 0.00000 Na 0.00000 0.72160 0.50000 Ca 0.00000 0.72160 0.50000 K 0.47474 0.00000 0.53345 O1 0.11082 0.91458 0.89098 O2 0.11926 0.83062 0.39263 F3 0.10138 0.00000 0.38842 O4 0.36135 0.75374 0.55912 O5 0.34204 0.87221 0.25110 O6 0.33865 0.88144 0.75141 O7 0.33146 0.00000 0.02643 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 0.01610 0.01600 0.01518 0.00148 0.00363 -0.00030 Si2 0.01648 0.01724 0.01449 0.00204 0.00330 0.00033 Mg1 0.02383 0.02143 0.01755 0.00000 0.00512 0.00000 Mg2 0.02385 0.02414 0.02245 0.00000 0.00409 0.00000 Mg3 0.02545 0.02015 0.01990 0.00000 0.00909 0.00000 Na 0.05146 0.02872 0.02965 0.00000 -0.00761 0.00000 Ca 0.05146 0.02872 0.02965 0.00000 -0.00761 0.00000 K 0.08972 0.07068 0.06445 0.00000 -0.02758 0.00000 O1 0.01823 0.02416 0.02156 0.00102 0.00531 -0.00202 O2 0.01757 0.02778 0.02110 0.00437 0.00275 -0.00224 F3 0.03351 0.03032 0.02779 0.00000 0.00129 0.00000 O4 0.03923 0.02290 0.03043 0.01270 0.00736 0.00305 O5 0.02551 0.03400 0.02119 0.00119 0.00529 0.01005 O6 0.02411 0.03316 0.02313 -0.00101 0.00811 -0.00994 O7 0.03066 0.01582 0.03668 0.00000 0.00530 0.00000