data_[Na4Cu4O8]
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
  O  3.4400  0.6000  1.2600
]
_symmetry_space_group_name_H-M [P-1]
_cell_length_a [5.5201]
_cell_length_b [5.5630]
_cell_length_c [7.1552]
_cell_angle_alpha [80.8876]
_cell_angle_beta [88.0804]
_cell_angle_gamma [75.4124]
_symmetry_Int_Tables_number [2]
_chemical_formula_structural [NaCuO2]
_chemical_formula_sum '[Na4 Cu4 O8]'
_cell_volume [209.9536]
_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  2  0.2272  0.6032  0.0661  1.0
  Na  Na1  1  0.0000  0.5000  0.5000  1.0
  Na  Na2  1  0.5000  0.5000  0.5000  1.0
  Cu  Cu3  2  0.1177  0.9495  0.7174  1.0
  Cu  Cu4  2  0.3841  0.0495  0.2756  1.0
  O  O5  2  0.0764  0.2786  0.2208  1.0
  O  O6  2  0.1891  0.8181  0.3239  1.0
  O  O7  2  0.3110  0.1777  0.6689  1.0
  O  O8  2  0.4230  0.7187  0.7763  1.0
]