data_BrCl
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.81
_cell_length_b   3.81
_cell_length_c   8.19
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   BrCl
_chemical_formula_sum   'Br2 Cl2'
_cell_volume   102.83
_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
  Br  Br0  1  0.9  0.1  0.16  1.0
  Br  Br1  1  0.0  0.2  0.04  1.0
  Cl  Cl2  1  0.9  0.1  0.05  1.0
  Cl  Cl3  1  0.0  0.2  0.14  1.0

data_BrCl
_symmetry_space_group_name_H-M   C2/m
_cell_length_a   3.81
_cell_length_b   6.59
_cell_length_c   8.19
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   12
_chemical_formula_structural   BrCl
_chemical_formula_sum   'Br4 Cl4'
_cell_volume   205.66
_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
  Br  Br0  4  0.05  0.5  0.94  1.0
  Cl  Cl1  4  0.05  0.5  0.04  1.0

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