data_Hg2PbBr
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.56
_cell_length_b   6.56
_cell_length_c   6.56
_cell_angle_alpha   139.62
_cell_angle_beta   139.62
_cell_angle_gamma   58.44
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Hg2PbBr
_chemical_formula_sum   'Hg2 Pb1 Br1'
_cell_volume   117.2
_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  Hg1  1  0.26  0.0  0.86  1.0
  Hg  Hg2  1  0.0  0.26  0.86  1.0
  Pb  Pb3  1  0.0  0.0  0.72  1.0
  Br  Br0  1  0.0  0.0  0.0  1.0

data_Hg2PbBr
_symmetry_space_group_name_H-M   Cm
_cell_length_a   6.4
_cell_length_b   6.4
_cell_length_c   6.56
_cell_angle_alpha   90.0
_cell_angle_beta   119.22
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Hg2PbBr
_chemical_formula_sum   'Hg4 Pb2 Br2'
_cell_volume   234.4
_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  4  0.13  0.13  0.4  1.0
  Pb  Pb1  2  0.0  0.0  0.28  1.0
  Br  Br2  2  0.0  0.0  0.0  1.0

Hg Hg Pb Br