data_[Na4Cu2I8]
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
  I  2.6600  1.4000  1.2733
]
_symmetry_space_group_name_H-M [P2_1/m]
_cell_length_a [7.9037]
_cell_length_b [6.9930]
_cell_length_c [9.0136]
_cell_angle_alpha [90.0000]
_cell_angle_beta [106.4455]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [11]
_chemical_formula_structural [Na2CuI4]
_chemical_formula_sum '[Na4 Cu2 I8]'
_cell_volume [477.8029]
_cell_formula_units_Z [2]
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  0.2307  0.7500  0.9326  1.0
  Na  Na1  2  0.2337  0.7500  0.4356  1.0
  Cu  Cu2  2  0.2532  0.2500  0.1858  1.0
  I  I3  4  0.4985  0.5067  0.2509  1.0
  I  I4  2  0.0700  0.2500  0.3844  1.0
  I  I5  2  0.0718  0.2500  0.8980  1.0
]