data_[Na8Cu8Se8]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Na  0.9300  1.8000  1.1600
  Cu  1.9000  1.3500  0.8200
  Se  2.5500  1.1500  1.0133
]
_symmetry_space_group_name_H-M [Cc]
_cell_length_a [10.0872]
_cell_length_b [8.2967]
_cell_length_c [8.0179]
_cell_angle_alpha [90.0000]
_cell_angle_beta [128.2397]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [9]
_chemical_formula_structural [NaCuSe]
_chemical_formula_sum '[Na8 Cu8 Se8]'
_cell_volume [527.0384]
_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  4  0.1665  0.6440  0.6997  1.0
  Na  Na1  4  0.4708  0.4271  0.7990  1.0
  Cu  Cu2  4  0.3238  0.0644  0.8200  1.0
  Cu  Cu3  4  0.4679  0.1422  0.2025  1.0
  Se  Se4  4  0.2702  0.3410  0.9402  1.0
  Se  Se5  4  0.3260  0.1292  0.5386  1.0
]