data_[Na8Se8]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Na  0.9300  1.8000  1.1600
  Se  2.5500  1.1500  1.0133
]
_symmetry_space_group_name_H-M [Pnma]
_cell_length_a [5.9741]
_cell_length_b [8.3213]
_cell_length_c [8.3080]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [62]
_chemical_formula_structural [NaSe]
_chemical_formula_sum '[Na8 Se8]'
_cell_volume [413.0094]
_cell_formula_units_Z [8]
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  8  0.2255  0.5373  0.1203  1
  Se  Se1  4  0.0045  0.2500  0.4028  1
  Se  Se2  4  0.1952  0.2500  0.8997  1
]