data_[Na4Cu4Se12]
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 [C2/c]
_cell_length_a [7.9459]
_cell_length_b [8.8307]
_cell_length_c [7.3789]
_cell_angle_alpha [90.0000]
_cell_angle_beta [109.9699]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [15]
_chemical_formula_structural [NaCuSe3]
_chemical_formula_sum '[Na4 Cu4 Se12]'
_cell_volume [486.6299]
_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  0.2183  0.7500  1.0
  Cu  Cu1  4  0.0000  0.4366  0.2500  1.0
  Se  Se2  8  0.2007  0.4797  0.5817  1.0
  Se  Se3  4  0.0000  0.1500  0.2500  1.0
]