data_global _chemical_name_mineral 'Fluorapophyllite-(K)' loop_ _publ_author_name 'Prince E' _journal_name_full 'American Mineralogist' _journal_volume 56 _journal_year 1971 _journal_page_first 1243 _journal_page_last 1251 _publ_section_title ; Refinement of the crystal structure of apophyllite III. Determination of the hydrogen positions by neutron diffraction ; _database_code_amcsd 257 _chemical_compound_source 'Centerville, Virginia, USA' _chemical_formula_sum 'K Ca4 Si8 O28 F H16' _cell_length_a 8.96 _cell_length_b 8.96 _cell_length_c 15.8 _cell_angle_alpha 90.0 _cell_angle_beta 90.0 _cell_angle_gamma 90.0 _cell_volume 1268.449 _exptl_crystal_density_diffrn 2.375 _symmetry_space_group_name_H-M 'P 4/m n c' loop_ _space_group_symop_operation_xyz 'x,y,z' '1/2-y,1/2-x,1/2+z' '1/2+y,1/2+x,1/2-z' 'y,-x,-z' '-y,x,z' '1/2+x,1/2-y,1/2+z' '1/2-x,1/2+y,1/2-z' 'x,y,-z' '-x,-y,z' '1/2+y,1/2+x,1/2+z' '1/2-y,1/2-x,1/2-z' '-y,x,-z' 'y,-x,z' '1/2-x,1/2+y,1/2+z' '1/2+x,1/2-y,1/2-z' '-x,-y,-z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_occupancy K 0.0 0.0 0.5 1.0 Ca 0.111 0.2473 0.0 1.0 Si 0.2267 0.0866 0.1896 1.0 O1 0.3636 0.1364 0.25 1.0 O2 0.0846 0.1897 0.2169 1.0 O3 0.2657 0.1018 0.0924 1.0 F 0.0 0.0 0.0 1.0 O4 0.2154 0.45 0.0893 1.0 H1 0.449 0.173 0.0889 1.0 H2 0.2244 0.4255 0.1481 0.875 H3 0.0 0.0 0.0651 0.5 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 K 0.01773 0.01773 0.04812 0.0 0.0 0.0 Ca 0.01051 0.01001 0.01 -0.00101 0.0 0.0 Si 0.00532 0.00722 0.00836 -0.00025 -0.00025 0.00076 O1 0.00811 0.00811 0.01076 -0.00025 -0.00253 -0.00253 O2 0.00747 0.01355 0.01748 0.00431 -0.00139 -0.00329 O3 0.0138 0.0133 0.00545 -0.00013 -0.00038 -0.00025 F 0.00709 0.00709 0.02039 0.0 0.0 0.0 O4 0.03103 0.01431 0.01862 -0.00076 0.00139 -0.00367 H1 0.02533 0.03293 0.03293 -0.00126 0.00456 -0.00076 H2 0.06332 0.03293 0.01647 0.0 -0.00633 0.00127 H3 0.08992 0.08992 0.03546 0.0 0.0 0.0