data_Ca2CuHg
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.05
_cell_length_b   8.05
_cell_length_c   8.05
_cell_angle_alpha   30.15
_cell_angle_beta   30.15
_cell_angle_gamma   30.15
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ca2CuHg
_chemical_formula_sum   'Ca2 Cu1 Hg1'
_cell_volume   116.57
_cell_formula_units_Z   1
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
loop_
 _atom_site_type_symbol
 _atom_site_label
 _atom_site_symmetry_multiplicity
 _atom_site_fract_x
 _atom_site_fract_y
 _atom_site_fract_z
 _atom_site_occupancy
  Ca  Ca0  1  0.0  0.0  0.99  1.0
  Ca  Ca1  1  0.0  0.0  0.04  1.0
  Cu  Cu2  1  0.0  0.0  0.0  1.0
  Hg  Hg3  1  0.0  0.0  0.52  1.0

data_Ca2CuHg
_symmetry_space_group_name_H-M   Cm
_cell_length_a   7.25
_cell_length_b   4.19
_cell_length_c   8.05
_cell_angle_alpha   90.0
_cell_angle_beta   107.48
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Ca2CuHg
_chemical_formula_sum   'Ca4 Cu2 Hg2'
_cell_volume   233.14
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  'x, -y, z'
  3  'x+1/2, y+1/2, z'
  4  'x+1/2, -y+1/2, z'
loop_
 _atom_site_type_symbol
 _atom_site_label
 _atom_site_symmetry_multiplicity
 _atom_site_fract_x
 _atom_site_fract_y
 _atom_site_fract_z
 _atom_site_occupancy
  Ca  Ca0  2  0.0  0.0  0.01  1.0
  Ca  Ca1  2  0.0  0.0  0.96  1.0
  Cu  Cu2  2  0.0  0.0  0.0  1.0
  Hg  Hg3  2  0.0  0.0  0.48  1.0

Ca Ca Cu Hg
Ca Ca Cu Hg 0 2 o o + 0 1 o o + 0 3 o o + 0 3 - o + 0 3 o - + 0 3 o o o 1 2 o o o 1 3 o + - 1 3 + o - 1 3 o o o 1 3 o o - 2 3 o o o 2 3 o o - 3 3 o + - 3 3 + - o 3 3 + o - 