data_[Rb2Ta2Nb2O12]
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]
_cell_length_a [5.4827]
_cell_length_b [9.7379]
_cell_length_c [6.0945]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.9155]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [5]
_chemical_formula_structural [RbTaNbO6]
_chemical_formula_sum '[Rb2 Ta2 Nb2 O12]'
_cell_volume [325.3442]
_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  0.9997  0.0000  1.0
  Ta  Ta1  2  0.0000  0.6795  0.5000  1.0
  Nb  Nb2  2  0.0000  0.3199  0.5000  1.0
  O  O3  4  0.0886  0.5013  0.3424  1.0
  O  O4  4  0.2017  0.7899  0.3068  1.0
  O  O5  4  0.2038  0.2093  0.3073  1.0
]