data_[Na4Al4Se8]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Na  0.9300  1.8000  1.1600
  Al  1.6100  1.2500  0.6750
  Se  2.5500  1.1500  1.0133
]
_symmetry_space_group_name_H-M [Cmc2_1]
_cell_length_a [3.9058]
_cell_length_b [15.7578]
_cell_length_c [6.7534]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [36]
_chemical_formula_structural [NaAlSe2]
_chemical_formula_sum '[Na4 Al4 Se8]'
_cell_volume [415.6507]
_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  0.1847  0.7236  1.0
  Al  Al1  4  0.0000  0.4257  0.7445  1.0
  Se  Se2  4  0.0000  0.1625  0.1585  1.0
  Se  Se3  4  0.0000  0.4375  0.0986  1.0
]