data_global _chemical_name_mineral 'Richterite' loop_ _publ_author_name 'Senda K' 'Ishida K' 'Jenkins D M' _journal_name_full 'American Mineralogist' _journal_volume 90 _journal_year 2005 _journal_page_first 1062 _journal_page_last 1071 _publ_section_title ; X-ray Rietveld refinement and FTIR spectra of synthetic (Si,Ge)-richterites Sample: Ge4Ri, Si48Ge52 ; _database_code_amcsd 0003794 _chemical_formula_sum 'Na1.47 Ca.98 Mg5 (Si3.88 Ge4.12) O24 H2' _cell_length_a 10.1237 _cell_length_b 18.147 _cell_length_c 5.3386 _cell_angle_alpha 90 _cell_angle_beta 105.067 _cell_angle_gamma 90 _cell_volume 947.063 _exptl_crystal_density_diffrn 3.467 _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 NaA 0.00000 0.50000 0.00000 0.45000 0.03394 Ca4 0.00000 0.27730 0.50000 0.49000 0.02001 Na4 0.00000 0.27730 0.50000 0.51000 0.02001 Mg1 0.00000 0.08820 0.50000 1.00000 0.00595 Mg2 0.00000 0.17830 0.00000 1.00000 0.00773 Mg3 0.00000 0.00000 0.00000 1.00000 0.00532 Si1 0.28030 0.08500 0.30400 0.58000 0.00646 Ge1 0.28030 0.08500 0.30400 0.42000 0.00646 Si2 0.28560 0.17310 0.80870 0.39000 0.00633 Ge2 0.28560 0.17310 0.80870 0.61000 0.00633 O1 0.11300 0.08390 0.21700 1.00000 0.00874 O2 0.11300 0.17020 0.72600 1.00000 0.00811 O-H3 0.10600 0.00000 0.72500 1.00000 0.00811 O4 0.35500 0.24950 0.79000 1.00000 0.01216 O5 0.34600 0.13650 0.12100 1.00000 0.01089 O6 0.34200 0.10990 0.62400 1.00000 0.01064 O7 0.33900 0.00000 0.26200 1.00000 0.01178