data_[Na1Nb2Se4]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Na  0.9300  1.8000  1.1600
  Nb  1.6000  1.4500  0.8200
  Se  2.5500  1.1500  1.0133
]
_symmetry_space_group_name_H-M [P3m1]
_cell_length_a [3.5474]
_cell_length_b [3.5474]
_cell_length_c [15.2427]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [120.0000]
_symmetry_Int_Tables_number [156]
_chemical_formula_structural [Na(NbSe2)2]
_chemical_formula_sum '[Na1 Nb2 Se4]'
_cell_volume [166.1190]
_cell_formula_units_Z [1]
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  1  0.0000  0.0000  0.0005  1.0
  Nb  Nb1  1  0.0000  0.0000  0.2512  1.0
  Nb  Nb2  1  0.3333  0.6667  0.7489  1.0
  Se  Se3  1  0.6667  0.3333  0.1409  1.0
  Se  Se4  1  0.6667  0.3333  0.3588  1.0
  Se  Se5  1  0.6667  0.3333  0.6413  1.0
  Se  Se6  1  0.6667  0.3333  0.8593  1.0
]