data_SiBr
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.8
_cell_length_b   3.8
_cell_length_c   8.34
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   SiBr
_chemical_formula_sum   'Si2 Br2'
_cell_volume   104.27
_cell_formula_units_Z   2
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  0.0  0.19  0.76  1.0
  Si  Si3  1  0.9  0.1  0.58  1.0
  Br  Br0  1  0.0  0.19  0.65  1.0
  Br  Br1  1  0.9  0.1  0.69  1.0

data_SiBr
_symmetry_space_group_name_H-M   C2/m
_cell_length_a   3.8
_cell_length_b   6.58
_cell_length_c   8.34
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   12
_chemical_formula_structural   SiBr
_chemical_formula_sum   'Si4 Br4'
_cell_volume   208.55
_cell_formula_units_Z   4
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-x, -y, -z'
  3  '-x, y, -z'
  4  'x, -y, z'
  5  'x+1/2, y+1/2, z'
  6  '-x+1/2, -y+1/2, -z'
  7  '-x+1/2, y+1/2, -z'
  8  '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  4  0.05  0.5  0.59  1.0
  Br  Br1  4  0.05  0.5  0.48  1.0

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