data_Si2AsBr
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.37
_cell_length_b   3.37
_cell_length_c   7.05
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Si2AsBr
_chemical_formula_sum   'Si2 As1 Br1'
_cell_volume   80.22
_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  0.69  0.69  0.64  1.0
  Si  Si3  1  0.69  0.69  0.4  1.0
  As  As0  1  0.0  0.0  0.0  1.0
  Br  Br1  1  0.0  0.0  0.52  1.0

data_Si2AsBr
_symmetry_space_group_name_H-M   Cm
_cell_length_a   4.77
_cell_length_b   4.77
_cell_length_c   7.05
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Si2AsBr
_chemical_formula_sum   'Si4 As2 Br2'
_cell_volume   160.44
_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  0.19  0.5  0.4  1.0
  Si  Si1  2  0.19  0.5  0.64  1.0
  As  As2  2  0.0  0.0  0.0  1.0
  Br  Br3  2  0.0  0.0  0.52  1.0

Si Si As Br
Si Si As Br 0 3 + + o 0 1 o o o 0 2 + + + 0 2 + o + 0 2 o + + 1 3 + + o 1 2 + + o 1 2 + o o 1 2 o + o 2 2 + o o 2 2 o + o 2 3 o o - 2 3 o o o 