data_5000039
_chemical_name_systematic          'Calcium sulfate dihydrate'
_chemical_name_mineral             'Gypsum'
loop_
_publ_author_name
  'Cole, W F'
  'Lancucki, C J'
_journal_name_full                 'Acta Crystallographica B (24,1968-38,1982)'
_journal_volume                    30
_journal_year                      1974
_journal_page_first                921
_journal_page_last                 929
_cell_length_a                     5.670(2)
_cell_length_b                     15.201(2)
_cell_length_c                     6.533(2)
_cell_angle_alpha                  90
_cell_angle_beta                   118.60(7)
_cell_angle_gamma                  90
_cell_volume                       494.4
_cell_formula_units_Z              4
_exptl_crystal_density_meas        2.31
_symmetry_space_group_name_H-M     'I 1 2/c 1'
_symmetry_Int_Tables_number        15
_symmetry_cell_setting             monoclinic
loop_
_symmetry_equiv_pos_as_xyz
  'x,y,z'
  'x,-y,1/2+z'
  '-x,-y,-z'
  '-x,y,1/2-z'
  '1/2+x,1/2+y,1/2+z'
  '1/2+x,1/2-y,z'
  '1/2-x,1/2-y,1/2-z'
  '1/2-x,1/2+y,-z'
loop_
_atom_type_symbol
_atom_type_oxidation_number
  Ca2+   2.000
  S6+    6.000
  O2-   -2.000
  H1+    1.000
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 e 0.5 0.0787(6) 0.25 1.  0 d
  S1    S6+    4 e 0. 0.0784(7) 0.75 1.  0 d
  O1    O2-    8 f 0.9623(10) 0.1314(5) 0.5515(9) 1.  0 d
  O2    O2-    8 f 0.7586(10) 0.0216(5) 0.6674(8) 1.  0 d
  O3    O2-    8 f 0.3784(12) 0.1824(6) 0.4597(11) 1.  2 d
  H1    H1+    8 f -1. -1. -1. 2.  0 dum
_refine_ls_R_factor_all            0.011