data_[Ca2Nb8O16]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Ca  1.0000  1.8000  1.1400
  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 [10.4192]
_cell_length_b [6.0905]
_cell_length_c [7.8376]
_cell_angle_alpha [90.0000]
_cell_angle_beta [129.6596]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [12]
_chemical_formula_structural [CaNb4O8]
_chemical_formula_sum '[Ca2 Nb8 O16]'
_cell_volume [382.8934]
_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
  Nb  Nb1  4  0.0000  0.2748  0.0000  1
  Nb  Nb2  4  0.2255  0.5000  0.9716  1
  O  O3  8  0.0727  0.2316  0.7983  1
  O  O4  4  0.1649  0.0000  0.1724  1
  O  O5  4  0.2035  0.5000  0.2212  1
]