data_Bi2F
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.7
_cell_length_b   6.7
_cell_length_c   3.25
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Bi2F
_chemical_formula_sum   'Bi4 F2'
_cell_volume   146.19
_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
  Bi  Bi0  1  0.74  0.74  0.0  1.0
  Bi  Bi1  1  0.96  0.96  0.0  1.0
  Bi  Bi2  1  0.09  0.61  0.63  1.0
  Bi  Bi3  1  0.61  0.09  0.63  1.0
  F  F4  1  0.0  0.0  0.0  1.0
  F  F5  1  0.35  0.35  0.63  1.0

data_Bi2F
_symmetry_space_group_name_H-M   Cm
_cell_length_a   9.48
_cell_length_b   9.48
_cell_length_c   3.25
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Bi2F
_chemical_formula_sum   'Bi8 F4'
_cell_volume   292.38
_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+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
  Bi  Bi0  4  0.35  0.26  0.63  1.0
  Bi  Bi1  2  0.24  0.5  0.0  1.0
  Bi  Bi2  2  0.46  0.5  0.0  1.0
  F  F3  2  0.0  0.0  0.0  1.0
  F  F4  2  0.35  0.0  0.63  1.0

Bi Bi Bi Bi F F