data_Si2BiAs
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.57
_cell_length_b   3.57
_cell_length_c   6.61
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Si2BiAs
_chemical_formula_sum   'Si2 Bi1 As1'
_cell_volume   84.13
_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  Si2  1  0.78  0.78  0.38  1.0
  Si  Si3  1  0.78  0.78  0.24  1.0
  Bi  Bi1  1  0.0  0.0  0.31  1.0
  As  As0  1  0.0  0.0  0.0  1.0

data_Si2BiAs
_symmetry_space_group_name_H-M   Cm
_cell_length_a   5.04
_cell_length_b   5.04
_cell_length_c   6.61
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Si2BiAs
_chemical_formula_sum   'Si4 Bi2 As2'
_cell_volume   168.25
_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  0.28  0.5  0.24  1.0
  Si  Si1  2  0.28  0.5  0.38  1.0
  Bi  Bi2  2  0.0  0.0  0.31  1.0
  As  As3  2  0.0  0.0  0.0  1.0

Si Si Bi As
Si Si Bi As 0 1 o o o 0 2 + + o 1 2 + + o 1 3 + + o 2 3 o o o 