data_[Na8Ir4O20]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Na  0.9300  1.8000  1.1600
  Ir  2.2000  1.3500  0.7650
  O  3.4400  0.6000  1.2600
]
_symmetry_space_group_name_H-M [Cmcm]
_cell_length_a [3.8237]
_cell_length_b [11.9061]
_cell_length_c [10.8950]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [63]
_chemical_formula_structural [Na2IrO5]
_chemical_formula_sum '[Na8 Ir4 O20]'
_cell_volume [496.0007]
_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  8  0.0000  0.1380  0.5622  1.0
  Ir  Ir1  4  0.0000  0.1574  0.2500  1.0
  O  O2  8  0.0000  0.0458  0.1309  1.0
  O  O3  8  0.0000  0.2667  0.1256  1.0
  O  O4  4  0.0000  0.3355  0.7500  1.0
]