data_SeF2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.76
_cell_length_b   5.76
_cell_length_c   3.26
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   SeF2
_chemical_formula_sum   'Se2 F4'
_cell_volume   108.08
_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
  Se  Se4  1  0.0  0.0  0.0  1.0
  Se  Se5  1  0.88  0.88  0.63  1.0
  F  F0  1  0.98  0.98  0.0  1.0
  F  F1  1  0.78  0.78  0.0  1.0
  F  F2  1  0.86  0.9  0.63  1.0
  F  F3  1  0.9  0.86  0.63  1.0

data_SeF2
_symmetry_space_group_name_H-M   Cm
_cell_length_a   8.14
_cell_length_b   8.14
_cell_length_c   3.26
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   SeF2
_chemical_formula_sum   'Se4 F8'
_cell_volume   216.17
_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
  Se  Se0  2  0.0  0.0  0.0  1.0
  Se  Se1  2  0.38  0.5  0.63  1.0
  F  F2  4  0.38  0.48  0.63  1.0
  F  F3  2  0.28  0.5  0.0  1.0
  F  F4  2  0.48  0.5  0.0  1.0

Se Se F F F F
Se Se F F F F 0 2 - - o 1 4 o o o 1 5 o o o 1 3 o o + 2 3 o o o 3 5 o o - 3 4 o o - 