data_global _chemical_name_mineral 'Richterite' loop_ _publ_author_name 'Yang H' 'Konzett J' 'Prewitt C T' 'Fei Y' _journal_name_full 'American Mineralogist' _journal_volume 84 _journal_year 1999 _journal_page_first 681 _journal_page_last 684 _publ_section_title ; Single-crystal structure refinement of synthetic K-substituted potassic richterite, K(KCa)Mg5Si8O22(OH)2 ; _database_code_amcsd 0002223 _chemical_formula_sum 'Mg5 Ca K3 Si8 H2 O24' _cell_length_a 10.1926 _cell_length_b 18.1209 _cell_length_c 5.2736 _cell_angle_alpha 90 _cell_angle_beta 105.514 _cell_angle_gamma 90 _cell_volume 938.540 _exptl_crystal_density_diffrn 3.148 _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 Mg1 0.00000 0.08890 0.50000 1.00000 ? Mg2 0.00000 0.18000 0.00000 1.00000 ? Mg3 0.00000 0.00000 0.00000 1.00000 ? Ca4 0.00000 0.28190 0.50000 0.50000 ? K4 0.00000 0.28190 0.50000 0.50000 ? Si1 0.27060 0.08470 0.30650 1.00000 ? Si2 0.28120 0.17080 0.81310 1.00000 ? K 0.01300 0.50000 0.02800 1.00000 ? H 0.20200 0.00000 0.74700 1.00000 0.01646 O1 0.10830 0.08690 0.22040 1.00000 ? O2 0.11750 0.16890 0.72980 1.00000 ? O3 0.10380 0.00000 0.71880 1.00000 ? O4 0.35890 0.24630 0.80880 1.00000 ? O5 0.33990 0.12890 0.10570 1.00000 ? O6 0.33390 0.11450 0.60500 1.00000 ? O7 0.32710 0.00000 0.30470 1.00000 ? 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 Mg1 0.00684 0.00832 0.00680 0.00000 0.00025 0.00000 Mg2 0.00880 0.00665 0.00916 0.00000 0.00202 0.00000 Mg3 0.00489 0.00665 0.00641 0.00000 0.00101 0.00000 Ca4 0.01319 0.01164 0.01478 0.00000 0.00632 0.00000 K4 0.01319 0.01164 0.01478 0.00000 0.00632 0.00000 Si1 0.00586 0.00665 0.00510 0.00000 0.00025 -0.00093 Si2 0.00684 0.00665 0.00523 -0.00180 -0.00076 -0.00047 K 0.00195 0.02495 0.01557 0.00000 -0.00152 0.00000 O1 0.00733 0.00665 0.00536 -0.00090 0.00025 -0.00047 O2 0.00831 0.01497 0.00942 -0.00090 0.00051 -0.00233 O3 0.00831 0.00832 0.00955 0.00000 0.00177 0.00000 O4 0.02101 0.01164 0.01308 -0.00902 -0.00278 -0.00047 O5 0.00831 0.01331 0.00667 0.00090 0.00051 0.00327 O6 0.01124 0.01164 0.00602 -0.00090 -0.00202 -0.00327 O7 0.00782 0.00665 0.01530 0.00000 0.00126 0.00000