data_global _chemical_name_mineral 'Matlockite' loop_ _publ_author_name 'Bannister F A' 'Hey M H' _journal_name_full 'Mineralogical Magazine' _journal_volume 23 _journal_year 1934 _journal_page_first 587 _journal_page_last 597 _publ_section_title ; The crystal-structure and optical properties of matlockite (PbFCl) ; _database_code_amcsd 0014434 _chemical_compound_source 'Matlock, Derbyshire, England' _chemical_formula_sum 'Pb F Cl' _cell_length_a 4.09 _cell_length_b 4.09 _cell_length_c 7.21 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 120.610 _exptl_crystal_density_diffrn 7.205 _symmetry_space_group_name_H-M 'P 4/n m m' loop_ _space_group_symop_operation_xyz 'x,y,z' '1/2-y,1/2-x,z' 'y,x,-z' 'y,-x,-z' '1/2-y,1/2+x,z' 'x,-y,z' '1/2-x,1/2+y,-z' '1/2+x,1/2+y,-z' '-x,-y,z' '1/2+y,1/2+x,z' '-y,-x,-z' '-y,x,-z' '1/2+y,1/2-x,z' '-x,y,z' '1/2+x,1/2-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 Pb 0.00000 0.50000 0.20800 F 0.00000 0.00000 0.00000 Cl 0.00000 0.50000 0.65000