data_[Na8Ni4Se12]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Na  0.9300  1.8000  1.1600
  Ni  1.9100  1.3500  0.7400
  Se  2.5500  1.1500  1.0133
]
_symmetry_space_group_name_H-M [C2/m]
_cell_length_a [6.6805]
_cell_length_b [11.6004]
_cell_length_c [7.2153]
_cell_angle_alpha [90.0000]
_cell_angle_beta [109.2408]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [12]
_chemical_formula_structural [Na2NiSe3]
_chemical_formula_sum '[Na8 Ni4 Se12]'
_cell_volume [527.9236]
_cell_formula_units_Z [4]
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
[
  Na  Na0  4  0.0000  0.1521  0.0000  1.0
  Na  Na1  2  0.0000  0.0000  0.5000  1.0
  Na  Na2  2  0.0000  0.5000  0.0000  1.0
  Ni  Ni3  4  0.0000  0.3333  0.5000  1.0
  Se  Se4  8  0.2381  0.3052  0.3094  1.0
  Se  Se5  4  0.1829  0.5000  0.6968  1.0
]