data_[Ba2Nb5O9]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Ba  0.8900  2.1500  1.4900
  Nb  1.6000  1.4500  0.8200
  O  3.4400  0.6000  1.2600
]
_symmetry_space_group_name_H-M [P4/mmm]
_cell_length_a [4.1965]
_cell_length_b [4.1965]
_cell_length_c [12.2743]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [123]
_chemical_formula_structural [Ba2Nb5O9]
_chemical_formula_sum '[Ba2 Nb5 O9]'
_cell_volume [216.1544]
_cell_formula_units_Z [1]
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
[
  Ba  Ba0  2  0.0000  0.0000  0.3323  1
  Nb  Nb1  2  0.0000  0.5000  0.0000  1
  Nb  Nb2  2  0.5000  0.5000  0.1633  1
  Nb  Nb3  1  0.5000  0.5000  0.5000  1
  O  O4  4  0.0000  0.5000  0.1733  1
  O  O5  2  0.0000  0.5000  0.5000  1
  O  O6  2  0.5000  0.5000  0.3378  1
  O  O7  1  0.0000  0.0000  0.0000  1
]