data_BiPb
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.46
_cell_length_b   3.46
_cell_length_c   10.88
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   104.1
_symmetry_Int_Tables_number   1
_chemical_formula_structural   BiPb
_chemical_formula_sum   'Bi2 Pb2'
_cell_volume   126.62
_cell_formula_units_Z   2
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
  Bi  Bi0  1  0.13  0.37  0.42  1.0
  Bi  Bi1  1  0.13  0.63  0.46  1.0
  Pb  Pb2  1  0.13  0.37  0.84  1.0
  Pb  Pb3  1  0.13  0.63  0.04  1.0

data_BiPb
_symmetry_space_group_name_H-M   P-1
_cell_length_a   3.46
_cell_length_b   3.46
_cell_length_c   10.88
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   104.1
_symmetry_Int_Tables_number   2
_chemical_formula_structural   BiPb
_chemical_formula_sum   'Bi2 Pb2'
_cell_volume   126.62
_cell_formula_units_Z   2
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
  Bi  Bi0  2  0.0  0.37  0.98  1.0
  Pb  Pb1  2  0.0  0.37  0.4  1.0

Bi Bi Pb Pb
Bi Bi Pb Pb 0 1 o o o 2 3 o o + 