data_[Rb2Na4Nb4O14]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Rb  0.8200  2.3500  1.6600
  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 [Imm2]
_cell_length_a [3.9278]
_cell_length_b [18.0330]
_cell_length_c [5.6895]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [44]
_chemical_formula_structural [RbNa2Nb2O7]
_chemical_formula_sum '[Rb2 Na4 Nb4 O14]'
_cell_volume [402.9876]
_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
[
  Rb  Rb0  2  0.0000  0.0000  0.0684  1
  Na  Na1  4  0.0000  0.2731  0.5596  1
  Nb  Nb2  4  0.0000  0.3918  0.0737  1
  O  O3  4  0.0000  0.1008  0.4928  1
  O  O4  4  0.0000  0.2925  0.9670  1
  O  O5  4  0.0000  0.3901  0.3927  1
  O  O6  2  0.0000  0.5000  0.9598  1
]