data_[Na2Nb4O10]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Na  0.9300  1.8000  1.1600
  Nb  1.6000  1.4500  0.8200
  O  3.4400  0.6000  1.2600
]
_symmetry_space_group_name_H-M [Immm]
_cell_length_a [3.2251]
_cell_length_b [5.3636]
_cell_length_c [10.7453]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [71]
_chemical_formula_structural [NaNb2O5]
_chemical_formula_sum '[Na2 Nb4 O10]'
_cell_volume [185.8744]
_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  0.0000  0.0000  0.0000  1
  Nb  Nb1  4  0.0000  0.5000  0.1823  1
  O  O2  8  0.0000  0.2577  0.3389  1
  O  O3  2  0.0000  0.5000  0.0000  1
]