data_[Rb6Nb2O12]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Rb  0.8200  2.3500  1.6600
  Nb  1.6000  1.4500  0.8200
  O  3.4400  0.6000  1.2600
]
_symmetry_space_group_name_H-M [P6_3/mmc]
_cell_length_a [6.8906]
_cell_length_b [6.8906]
_cell_length_c [10.8809]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [120.0000]
_symmetry_Int_Tables_number [194]
_chemical_formula_structural [Rb3NbO6]
_chemical_formula_sum '[Rb6 Nb2 O12]'
_cell_volume [447.4124]
_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  4  0.3333  0.6667  0.5800  1
  Rb  Rb1  2  0.0000  0.0000  0.0000  1
  Nb  Nb2  2  0.3333  0.6667  0.2500  1
  O  O3  12  0.1978  0.3956  0.1438  1
]