data_global _chemical_name_mineral 'Anhydrite' loop_ _publ_author_name 'Antao S' _journal_name_full 'Powder Diffraction' _journal_volume 26 _journal_year 2011 _journal_page_first 326 _journal_page_last 330 _publ_section_title ; Crystal-structure analysis of four mineral samples of anhydrite, Ca(SO4), using synchrotron high-resolution powder X-ray diffraction data ; _database_code_amcsd 0020857 _chemical_formula_sum 'Ca S O4' _cell_length_a 7.00071 _cell_length_b 6.99274 _cell_length_c 6.24125 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 305.535 _exptl_crystal_density_diffrn 2.960 _symmetry_space_group_name_H-M 'A m m a' loop_ _space_group_symop_operation_xyz 'x,y,z' 'x,1/2+y,1/2+z' '1/2+x,y,-z' '1/2+x,1/2+y,1/2-z' '1/2-x,-y,z' '1/2-x,1/2-y,1/2+z' 'x,-y,z' 'x,1/2-y,1/2+z' '-x,y,-z' '-x,1/2+y,1/2-z' '1/2-x,y,z' '1/2-x,1/2+y,1/2+z' '1/2+x,-y,-z' '1/2+x,1/2-y,1/2-z' '-x,-y,-z' '-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_U_iso_or_equiv Ca 0.75000 0.00000 0.34637 0.00810 S 0.25000 0.00000 0.15540 0.00710 O1 0.25000 0.17330 0.01640 0.00790 O2 0.07970 0.00000 0.29670 0.00770