data_5000040
_chemical_name_systematic          'Calcium sulfate'
_chemical_name_mineral             'Anhydrite'
_chemical_formula_structural       'Ca S O4'
_chemical_formula_sum              'Ca O4 S'
_publ_section_title
;
The crystal structure of anhydrite (Ca S O4)
;
loop_
_publ_author_name
  'Cheng, G C H'
  'Zussman, J'
_journal_name_full                 'Acta Crystallographica (1,1948-23,1967)'
_journal_volume                    16
_journal_year                      1963
_journal_page_first                767
_journal_page_last                 769
_cell_length_a                     6.991
_cell_length_b                     6.996
_cell_length_c                     6.238
_cell_angle_alpha                  90
_cell_angle_beta                   90
_cell_angle_gamma                  90
_cell_volume                       305.1
_cell_formula_units_Z              4
_symmetry_space_group_name_H-M     'A m m a'
_symmetry_Int_Tables_number        63
_symmetry_cell_setting             orthorhombic
loop_
_symmetry_equiv_pos_as_xyz
  'x,y,z'
  '-x,y,-z'
  '1/2-x,y,z'
  '1/2+x,y,-z'
  '-x,-y,-z'
  'x,-y,z'
  '1/2+x,-y,-z'
  '1/2-x,-y,z'
  'x,1/2+y,1/2+z'
  '-x,1/2+y,1/2-z'
  '1/2-x,1/2+y,1/2+z'
  '1/2+x,1/2+y,1/2-z'
  '-x,1/2-y,1/2-z'
  'x,1/2-y,1/2+z'
  '1/2+x,1/2-y,1/2-z'
  '1/2-x,1/2-y,1/2+z'
loop_
_atom_type_symbol
_atom_type_oxidation_number
  Ca2+   2.000
  S6+    6.000
  O2-   -2.000
loop_
_atom_site_label
_atom_site_type_symbol
_atom_site_symmetry_multiplicity
_atom_site_Wyckoff_symbol
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_occupancy
_atom_site_attached_hydrogens
_atom_site_calc_flag
  Ca1   Ca2+   4 c 0.75 0. 0.346 1.  0 d
  S1    S6+    4 c 0.25 0. 0.155 1.  0 d
  O1    O2-    8 g 0.25 0.171 0.015 1.  0 d
  O2    O2-    8 f 0.08 0. 0.298 1.  0 d
_refine_ls_R_factor_all            0.11