data_[Na4Si4Se8]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Na  0.9300  1.8000  1.1600
  Si  1.9000  1.1000  0.5400
  Se  2.5500  1.1500  1.0133
]
_symmetry_space_group_name_H-M [Pna2_1]
_cell_length_a [6.0983]
_cell_length_b [10.9802]
_cell_length_c [5.6330]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [33]
_chemical_formula_structural [NaSiSe2]
_chemical_formula_sum '[Na4 Si4 Se8]'
_cell_volume [377.1895]
_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  0.0412  0.3877  0.0628  1
  Si  Si1  4  0.0303  0.8850  0.0218  1
  Se  Se2  4  0.0443  0.1124  0.1003  1
  Se  Se3  4  0.0900  0.3419  0.5649  1
]