data_[K4Nb2Ni4Se8]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  K  0.8200  2.2000  1.5200
  Nb  1.6000  1.4500  0.8200
  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 [13.9356]
_cell_length_b [3.7514]
_cell_length_c [7.9420]
_cell_angle_alpha [90.0000]
_cell_angle_beta [106.9604]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [12]
_chemical_formula_structural [K2Nb(NiSe2)2]
_chemical_formula_sum '[K4 Nb2 Ni4 Se8]'
_cell_volume [397.1303]
_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
[
  K  K0  4  0.1356  0.0000  0.5617  1.0
  Nb  Nb1  2  0.0000  0.0000  0.0000  1.0
  Ni  Ni2  4  0.1687  0.5000  0.9826  1.0
  Se  Se3  4  0.0135  0.5000  0.7663  1.0
  Se  Se4  4  0.1980  0.0000  0.1695  1.0
]