data_SiGePb2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.57
_cell_length_b   3.57
_cell_length_c   7.78
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   SiGePb2
_chemical_formula_sum   'Si1 Ge1 Pb2'
_cell_volume   99.16
_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
  Si  Si3  1  0.0  0.0  0.39  1.0
  Ge  Ge0  1  0.78  0.78  0.33  1.0
  Pb  Pb1  1  0.0  0.0  0.48  1.0
  Pb  Pb2  1  0.78  0.78  0.26  1.0

data_SiGePb2
_symmetry_space_group_name_H-M   Cm
_cell_length_a   5.05
_cell_length_b   5.05
_cell_length_c   7.78
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   SiGePb2
_chemical_formula_sum   'Si2 Ge2 Pb4'
_cell_volume   198.33
_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
  Si  Si0  2  0.0  0.0  0.39  1.0
  Ge  Ge1  2  0.28  0.5  0.33  1.0
  Pb  Pb2  2  0.0  0.0  0.48  1.0
  Pb  Pb3  2  0.28  0.5  0.26  1.0

Si Ge Pb Pb
Si Ge Pb Pb 0 2 o o o 1 3 o o o 