data_CuSiBi2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.44
_cell_length_b   3.44
_cell_length_c   7.71
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   CuSiBi2
_chemical_formula_sum   'Cu1 Si1 Bi2'
_cell_volume   91.42
_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
  Cu  Cu2  1  0.0  0.0  0.85  1.0
  Si  Si3  1  0.0  0.0  0.0  1.0
  Bi  Bi0  1  0.72  0.72  0.04  1.0
  Bi  Bi1  1  0.72  0.72  0.67  1.0

data_CuSiBi2
_symmetry_space_group_name_H-M   Cm
_cell_length_a   4.87
_cell_length_b   4.87
_cell_length_c   7.71
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   CuSiBi2
_chemical_formula_sum   'Cu2 Si2 Bi4'
_cell_volume   182.85
_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  0.0  1.0
  Cu  Cu1  2  0.0  0.0  0.85  1.0
  Bi  Bi2  2  0.22  0.5  0.04  1.0
  Bi  Bi3  2  0.22  0.5  0.67  1.0

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