data_CaCuHg2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.46
_cell_length_b   3.46
_cell_length_c   7.4
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   CaCuHg2
_chemical_formula_sum   'Ca1 Cu1 Hg2'
_cell_volume   88.42
_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  0.85  1.0
  Cu  Cu1  1  0.73  0.73  0.54  1.0
  Hg  Hg2  1  0.0  0.0  0.26  1.0
  Hg  Hg3  1  0.73  0.73  0.85  1.0

data_CaCuHg2
_symmetry_space_group_name_H-M   Cm
_cell_length_a   4.89
_cell_length_b   4.89
_cell_length_c   7.4
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   CaCuHg2
_chemical_formula_sum   'Ca2 Cu2 Hg4'
_cell_volume   176.84
_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  0.85  1.0
  Cu  Cu1  2  0.23  0.5  0.54  1.0
  Hg  Hg2  2  0.0  0.0  0.26  1.0
  Hg  Hg3  2  0.23  0.5  0.85  1.0

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