data_[Na4Sr4Nb8O26]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Na  0.9300  1.8000  1.1600
  Sr  0.9500  2.0000  1.3200
  Nb  1.6000  1.4500  0.8200
  O  3.4400  0.6000  1.2600
]
_symmetry_space_group_name_H-M [Imm2]
_cell_length_a [7.5442]
_cell_length_b [7.5628]
_cell_length_c [10.7691]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [44]
_chemical_formula_structural [Na2Sr2Nb4O13]
_chemical_formula_sum '[Na4 Sr4 Nb8 O26]'
_cell_volume [614.4338]
_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  4  0.2393  0.0000  0.7681  1
  Sr  Sr1  4  0.0000  0.2395  0.9905  1
  Nb  Nb2  4  0.0000  0.2566  0.5103  1
  Nb  Nb3  4  0.2424  0.0000  0.2586  1
  O  O4  8  0.1905  0.1882  0.3714  1
  O  O5  8  0.1960  0.3062  0.6202  1
  O  O6  2  0.0000  0.0000  0.1795  1
  O  O7  2  0.0000  0.0000  0.5504  1
  O  O8  2  0.0000  0.0000  0.8781  1
  O  O9  2  0.0000  0.5000  0.4318  1
  O  O10  2  0.0000  0.5000  0.8135  1
]