data_global _chemical_name_mineral 'Richterite' loop_ _publ_author_name 'Della Ventura G' 'Robert J-L' 'Raudsepp M' 'Hawthorne F C' _journal_name_full 'American Mineralogist' _journal_volume 78 _journal_year 1993 _journal_page_first 633 _journal_page_last 640 _publ_section_title ; Site occupancies in monoclinic amphiboles: Rietveld structure refinement of synthetic magnesium cobalt potassium richterite Sample: KNi100 Atomic parameters from ICSD ; _database_code_amcsd 0001579 _chemical_formula_sum 'Si8 Ni5 (Na Ca) K O24 H2' _cell_length_a 10.0297 _cell_length_b 17.942 _cell_length_c 5.2576 _cell_angle_alpha 90 _cell_angle_beta 104.982 _cell_angle_gamma 90 _cell_volume 913.959 _exptl_crystal_density_diffrn 3.657 _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 Si1 0.27440 0.08520 0.30270 1.00000 0.00507 Si2 0.28490 0.17080 0.80550 1.00000 0.00507 Ni1 0.00000 0.08950 0.50000 1.00000 0.00760 Ni2 0.00000 0.17840 0.00000 1.00000 0.00760 Ni3 0.00000 0.00000 0.00000 1.00000 0.00760 Na 0.00000 0.27400 0.50000 0.50000 0.01140 Ca 0.00000 0.27400 0.50000 0.50000 0.01140 K 0.02310 0.50000 0.03800 0.50000 0.02913 O1 0.10500 0.08890 0.21240 1.00000 0.01013 O2 0.11690 0.16970 0.73290 1.00000 0.01013 O-H3 0.10710 0.00000 0.71320 1.00000 0.01013 O4 0.35930 0.24550 0.78550 1.00000 0.01013 O5 0.34700 0.13330 0.10930 1.00000 0.01393 O6 0.33750 0.11680 0.59930 1.00000 0.01393 O7 0.33360 0.00000 0.31370 1.00000 0.01520