data_[Ni2Se8]
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 [I4/m]
_cell_length_a [8.3730]
_cell_length_b [8.3730]
_cell_length_c [3.2693]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [87]
_chemical_formula_structural [NiSe4]
_chemical_formula_sum '[Ni2 Se8]'
_cell_volume [229.2053]
_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
[
  Ni  Ni0  2  0.0000  0.0000  0.0000  1
  Se  Se1  8  0.1035  0.2059  0.5000  1
]