data_Si3Bi
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.65
_cell_length_b   4.15
_cell_length_c   5.64
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Si3Bi
_chemical_formula_sum   'Si3 Bi1'
_cell_volume   85.55
_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  0.08  0.65  1.0
  Si  Si2  1  0.0  0.0  0.07  1.0
  Si  Si3  1  0.83  0.0  0.39  1.0
  Bi  Bi0  1  0.83  0.08  0.29  1.0

data_Si3Bi
_symmetry_space_group_name_H-M   P1
_cell_length_a   3.65
_cell_length_b   4.15
_cell_length_c   5.64
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Si3Bi
_chemical_formula_sum   'Si3 Bi1'
_cell_volume   85.55
_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  Si0  1  -0.0  0.08  0.65  1.0
  Si  Si1  1  0.0  0.0  0.07  1.0
  Si  Si2  1  0.83  0.0  0.39  1.0
  Bi  Bi3  1  0.83  0.08  0.29  1.0

Si Si Si Bi
Si Si Si Bi 0 2 - o o 1 3 - o o 2 3 o o o 