data_[Ca2Ta2Nb4O16]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Ca  1.0000  1.8000  1.1400
  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 [Cmmm]
_cell_length_a [6.8026]
_cell_length_b [7.0274]
_cell_length_c [6.4504]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [65]
_chemical_formula_structural [CaTaNb2O8]
_chemical_formula_sum '[Ca2 Ta2 Nb4 O16]'
_cell_volume [308.3610]
_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
[
  Ca  Ca0  2  0.0000  0.0000  0.5000  1.0
  Ta  Ta1  2  0.0000  0.0000  0.0000  1.0
  Nb  Nb2  4  0.0000  0.5000  0.2469  1.0
  O  O3  8  0.2072  0.0000  0.2167  1.0
  O  O4  4  0.0000  0.2903  0.0000  1.0
  O  O5  4  0.0000  0.3263  0.5000  1.0
]