data_[Ca8Nb4O4]
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 [Fm-3m]
_cell_length_a [7.2338]
_cell_length_b [7.2338]
_cell_length_c [7.2338]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [225]
_chemical_formula_structural [Ca2NbO]
_chemical_formula_sum '[Ca8 Nb4 O4]'
_cell_volume [378.5217]
_cell_formula_units_Z [4]
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  8  0.2500  0.2500  0.2500  1
  Nb  Nb1  4  0.0000  0.0000  0.5000  1
  O  O2  4  0.0000  0.0000  0.0000  1
]