data_IrSe
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.53
_cell_length_b   5.53
_cell_length_c   3.52
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   140.45
_symmetry_Int_Tables_number   1
_chemical_formula_structural   IrSe
_chemical_formula_sum   'Ir2 Se2'
_cell_volume   68.6
_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
  Ir  Ir0  1  0.87  0.88  0.88  1.0
  Ir  Ir1  1  0.87  0.12  0.64  1.0
  Se  Se2  1  0.87  0.42  0.88  1.0
  Se  Se3  1  0.87  0.58  0.64  1.0

data_IrSe
_symmetry_space_group_name_H-M   P-1
_cell_length_a   3.52
_cell_length_b   3.74
_cell_length_c   5.53
_cell_angle_alpha   109.77
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   2
_chemical_formula_structural   IrSe
_chemical_formula_sum   'Ir2 Se2'
_cell_volume   68.6
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-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
  Ir  Ir0  2  0.38  0.88  0.38  1.0
  Se  Se1  2  0.38  0.42  0.92  1.0

Ir Ir Se Se
Ir Ir Se Se 0 1 o + o 2 3 o o o 