data_FeHg
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.48
_cell_length_b   4.77
_cell_length_c   5.41
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   FeHg
_chemical_formula_sum   'Fe4 Hg4'
_cell_volume   141.46
_cell_formula_units_Z   4
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
  Fe  Fe0  1  0.91  0.19  0.98  1.0
  Fe  Fe1  1  0.83  0.58  0.69  1.0
  Fe  Fe2  1  0.65  0.19  0.72  1.0
  Fe  Fe3  1  0.57  0.58  0.43  1.0
  Hg  Hg4  1  0.37  0.19  0.68  1.0
  Hg  Hg5  1  0.37  0.58  0.98  1.0
  Hg  Hg6  1  0.11  0.19  0.44  1.0
  Hg  Hg7  1  0.11  0.58  0.73  1.0

data_FeHg
_symmetry_space_group_name_H-M   P-1
_cell_length_a   4.77
_cell_length_b   5.41
_cell_length_c   5.48
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   2
_chemical_formula_structural   FeHg
_chemical_formula_sum   'Fe4 Hg4'
_cell_volume   141.46
_cell_formula_units_Z   4
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-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
  Fe  Fe0  2  0.19  0.22  0.33  1.0
  Fe  Fe1  2  0.19  0.48  0.59  1.0
  Hg  Hg2  2  0.19  0.52  0.87  1.0
  Hg  Hg3  2  0.19  0.77  0.13  1.0

Fe Fe Fe Fe Hg Hg Hg Hg