data_[Rb2Ta4Nb2O16]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Rb  0.8200  2.3500  1.6600
  Ta  1.5000  1.4500  0.8200
  Nb  1.6000  1.4500  0.8200
  O  3.4400  0.6000  1.2600
]
_symmetry_space_group_name_H-M [C2/m]
_cell_length_a [9.0784]
_cell_length_b [6.2542]
_cell_length_c [7.4372]
_cell_angle_alpha [90.0000]
_cell_angle_beta [106.3616]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [12]
_chemical_formula_structural [RbTa2NbO8]
_chemical_formula_sum '[Rb2 Ta4 Nb2 O16]'
_cell_volume [405.1711]
_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  0.5000  1.0
  Ta  Ta1  4  0.0701  0.5000  0.7228  1.0
  Nb  Nb2  2  0.0000  0.0000  0.0000  1.0
  O  O3  8  0.0201  0.2352  0.8180  1.0
  O  O4  4  0.1363  0.5000  0.4988  1.0
  O  O5  4  0.2226  0.0000  0.1171  1.0
]