data_global _chemical_name_mineral 'Richterite' loop_ _publ_author_name 'Della Ventura G' 'Robert J-L' 'Beny J-M' 'Raudsepp M' 'Hawthorne F C' _journal_name_full 'American Mineralogist' _journal_volume 78 _journal_year 1993 _journal_page_first 980 _journal_page_last 987 _publ_section_title ; The OH-F substitution in Ti-rich potassium richterite: Rietveld structure refinement and FTIR and micro-Raman spectroscopic studies of synthetic amphiboles in the system K2O-Na2O-CaO-MgO-SiO2-TiO2-H2O-HF Sample Rich61 Atomic parameters from ICSD ; _database_code_amcsd 0001612 _chemical_formula_sum 'O22.8 (F1.2 Si7.6) Ti.4 Mg5 (Na Ca) K H.8' _cell_length_a 10.0262 _cell_length_b 18.0194 _cell_length_c 5.2871 _cell_angle_alpha 90 _cell_angle_beta 104.874 _cell_angle_gamma 90 _cell_volume 923.194 _exptl_crystal_density_diffrn 3.039 _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 O1 0.11180 0.08880 0.21300 1.00000 0.01013 O2 0.11530 0.17000 0.72550 1.00000 0.01013 O-H 0.10400 0.00000 0.71630 0.40000 0.01013 F 0.10400 0.00000 0.71630 0.60000 0.01013 O4 0.35460 0.24720 0.79200 1.00000 0.01013 O5 0.33830 0.12810 0.09570 1.00000 0.01393 O6 0.33830 0.11600 0.59180 1.00000 0.01393 O7 0.33260 0.00000 0.31050 1.00000 0.01520 Si1 0.27720 0.08560 0.29990 1.00000 0.00507 Si2 0.28440 0.17060 0.81180 0.90000 0.00507 Ti 0.28440 0.17060 0.81180 0.10000 0.00507 Mg1 0.00000 0.09000 0.50000 1.00000 0.00760 Mg2 0.00000 0.17890 0.00000 1.00000 0.00760 Mg3 0.00000 0.00000 0.00000 1.00000 0.00760 Na 0.00000 0.27620 0.50000 0.50000 0.01140 Ca 0.00000 0.27620 0.50000 0.50000 0.01140 K 0.02630 0.50000 0.05780 0.50000 0.02913