data_global _chemical_name_mineral 'Fluorapophyllite-(K)' loop_ _publ_author_name 'Chao G Y' _journal_name_full 'American Mineralogist' _journal_volume 56 _journal_year 1971 _journal_page_first 1234 _journal_page_last 1242 _publ_section_title ; The refinement of the crystal structure of apophyllite II. Determination of the hydrogen positions by X-ray diffraction Note: O1-B23 changed to match symmetry constraints ; _database_code_amcsd 256 _chemical_compound_source 'Mont. St. Hilaire, Quebec, Canada' _chemical_formula_sum 'K Ca4 Si8 O28 F H16' _cell_length_a 8.965 _cell_length_b 8.965 _cell_length_c 15.767 _cell_angle_alpha 90.0 _cell_angle_beta 90.0 _cell_angle_gamma 90.0 _cell_volume 1267.213 _exptl_crystal_density_diffrn 2.378 _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_U_iso_or_equiv K 0.0 0.0 0.5 2.0 Ca 0.1094 0.2466 0.0 2.0 Si 0.2256 0.0865 0.19 2.0 O1 0.3631 0.1369 0.25 2.0 O2 0.0846 0.1891 0.2178 2.0 O3 0.2636 0.1026 0.0923 2.0 F 0.0 0.0 0.0 2.0 O4 0.2131 0.4491 0.0898 2.0 H1 0.4515 0.177 0.0775 0.0442 H2 0.2362 0.4706 0.1198 0.17149 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 0.03101 0.03101 0.05511 0.0 0.0 0.0 Ca 0.01129 0.01304 0.01229 0.00018 0.0 0.0 Si 0.0093 0.0083 0.01208 0.00013 -0.00042 -8e-05 O1 0.01603 0.01603 0.01671 -0.00257 -0.00197 -0.00197 O2 0.01389 0.01828 0.02475 0.00507 -0.00468 -0.00442 O3 0.02036 0.01757 0.01429 0.00022 -0.00417 -0.0022 F 0.01089 0.01089 0.03249 0.0 0.0 0.0 O4 0.03626 0.0183 0.01825 0.00036 -0.00145 -0.0048