data_[Ni6Se6]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Ni  1.9100  1.3500  0.7400
  Se  2.5500  1.1500  1.0133
]
_symmetry_space_group_name_H-M [P31m]
_cell_length_a [6.4898]
_cell_length_b [6.4898]
_cell_length_c [20.0687]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [120.0000]
_symmetry_Int_Tables_number [157]
_chemical_formula_structural [NiSe]
_chemical_formula_sum '[Ni6 Se6]'
_cell_volume [731.9915]
_cell_formula_units_Z [6]
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
[
  Ni  Ni0  3  0.0000  0.3272  0.4246  1
  Ni  Ni1  2  0.3333  0.6667  0.5023  1
  Ni  Ni2  1  0.0000  0.0000  0.4885  1
  Se  Se3  3  0.0000  0.3184  0.5372  1
  Se  Se4  2  0.3333  0.6667  0.6247  1
  Se  Se5  1  0.0000  0.0000  0.3722  1
]