data_global _chemical_name_mineral 'Asisite' loop_ _publ_author_name 'Welch M D' _journal_name_full 'Mineralogical Magazine' _journal_volume 68 _journal_year 2004 _journal_page_first 247 _journal_page_last 254 _publ_section_title ; Pb-Si ordering in sheet-oxychloride minerals: the super-structure of asisite, nominally Pb7SiO8Cl2 ; _database_code_amcsd 0014572 _chemical_compound_source 'Kombat mine, Namibia' _chemical_formula_sum 'Pb3.5 Si.5 O4 Cl' _cell_length_a 3.8932 _cell_length_b 3.8932 _cell_length_c 22.803 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 345.625 _exptl_crystal_density_diffrn 8.059 _symmetry_space_group_name_H-M 'I 4/m m m' loop_ _space_group_symop_operation_xyz 'x,y,z' '1/2+x,1/2+y,1/2+z' '-y,-x,z' '1/2-y,1/2-x,1/2+z' 'y,x,-z' '1/2+y,1/2+x,1/2-z' 'y,-x,-z' '1/2+y,1/2-x,1/2-z' '-y,x,z' '1/2-y,1/2+x,1/2+z' 'x,-y,z' '1/2+x,1/2-y,1/2+z' '-x,y,-z' '1/2-x,1/2+y,1/2-z' 'x,y,-z' '1/2+x,1/2+y,1/2-z' '-x,-y,z' '1/2-x,1/2-y,1/2+z' 'y,x,z' '1/2+y,1/2+x,1/2+z' '-y,-x,-z' '1/2-y,1/2-x,1/2-z' '-y,x,-z' '1/2-y,1/2+x,1/2-z' 'y,-x,z' '1/2+y,1/2-x,1/2+z' '-x,y,z' '1/2-x,1/2+y,1/2+z' 'x,-y,-z' '1/2+x,1/2-y,1/2-z' '-x,-y,-z' '1/2-x,1/2-y,1/2-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 Pb1 0.00000 0.00000 0.08380 1.00000 0.01700 Pb2 0.00000 0.00000 0.30490 0.75000 0.01800 Si2 0.00000 0.00000 0.30490 0.25000 0.01800 O 0.00000 0.50000 0.14300 1.00000 0.05900 Cl 0.00000 0.00000 0.50000 1.00000 0.04300 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 Pb1 0.02200 0.02200 0.00700 0.00000 0.00000 0.00000 Pb2 0.03100 0.03100 0.01400 0.00000 0.00000 0.00000 Si2 0.03100 0.03100 0.01400 0.00000 0.00000 0.00000 O 0.06200 0.05800 0.05600 0.00000 0.00000 0.00000 Cl 0.03400 0.03400 0.06000 0.00000 0.00000 0.00000