data_Si2Sn2Bi
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.76
_cell_length_b   5.76
_cell_length_c   5.76
_cell_angle_alpha   125.71
_cell_angle_beta   125.71
_cell_angle_gamma   80.36
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Si2Sn2Bi
_chemical_formula_sum   'Si2 Sn2 Bi1'
_cell_volume   121.59
_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  Si1  1  0.0  0.0  0.59  1.0
  Si  Si2  1  0.0  0.0  0.21  1.0
  Sn  Sn3  1  0.0  0.63  0.2  1.0
  Sn  Sn4  1  0.63  0.0  0.2  1.0
  Bi  Bi0  1  0.0  0.0  0.0  1.0

data_Si2Sn2Bi
_symmetry_space_group_name_H-M   Cm
_cell_length_a   7.43
_cell_length_b   7.43
_cell_length_c   5.76
_cell_angle_alpha   90.0
_cell_angle_beta   130.18
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Si2Sn2Bi
_chemical_formula_sum   'Si4 Sn4 Bi2'
_cell_volume   243.18
_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  0.29  0.5  0.79  1.0
  Si  Si1  2  0.41  0.0  0.41  1.0
  Sn  Sn2  4  0.11  0.31  0.43  1.0
  Bi  Bi3  2  0.0  0.0  0.0  1.0

Si Si Sn Sn Bi