data_[Na4Fe4O8]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Na  0.9300  1.8000  1.1600
  Fe  1.8300  1.4000  0.8525
  O  3.4400  0.6000  1.2600
]
_symmetry_space_group_name_H-M [Pna2_1]
_cell_length_a [5.7884]
_cell_length_b [7.2092]
_cell_length_c [5.4502]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [33]
_chemical_formula_structural [NaFeO2]
_chemical_formula_sum '[Na4 Fe4 O8]'
_cell_volume [227.4368]
_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  0.0784  0.8775  0.9892  1.0
  Fe  Fe1  4  0.0692  0.3732  0.0003  1.0
  O  O2  4  0.0450  0.4087  0.3465  1.0
  O  O3  4  0.1113  0.8401  0.4189  1.0
]