data_HgPb2Se
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.39
_cell_length_b   4.39
_cell_length_c   6.22
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   HgPb2Se
_chemical_formula_sum   'Hg1 Pb2 Se1'
_cell_volume   120.05
_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
  Hg  Hg0  1  0.2  0.2  0.3  1.0
  Pb  Pb1  1  0.0  0.0  0.64  1.0
  Pb  Pb2  1  0.2  0.2  0.24  1.0
  Se  Se3  1  0.0  0.0  0.38  1.0

data_HgPb2Se
_symmetry_space_group_name_H-M   Cm
_cell_length_a   6.21
_cell_length_b   6.21
_cell_length_c   6.22
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   HgPb2Se
_chemical_formula_sum   'Hg2 Pb4 Se2'
_cell_volume   240.1
_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
  Hg  Hg0  2  0.2  0.0  0.3  1.0
  Pb  Pb1  2  0.0  0.0  0.64  1.0
  Pb  Pb2  2  0.2  0.0  0.24  1.0
  Se  Se3  2  0.0  0.0  0.38  1.0

Hg Pb Pb Se
Hg Pb Pb Se 0 2 o o o 0 3 o o o 1 3 o o o 2 3 o o o 