data_[Ca4Nb4Al4O20]
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
  Al  1.6100  1.2500  0.6750
  O  3.4400  0.6000  1.2600
]
_symmetry_space_group_name_H-M [C2/c]
_cell_length_a [6.8140]
_cell_length_b [9.0405]
_cell_length_c [7.4908]
_cell_angle_alpha [90.0000]
_cell_angle_beta [114.7429]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [15]
_chemical_formula_structural [CaNbAlO5]
_chemical_formula_sum '[Ca4 Nb4 Al4 O20]'
_cell_volume [419.0850]
_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  4  0.0000  0.3321  0.2500  1.0
  Nb  Nb1  4  0.0000  0.0000  0.0000  1.0
  Al  Al2  4  0.0000  0.3162  0.7500  1.0
  O  O3  8  0.1043  0.2049  0.6141  1.0
  O  O4  8  0.1905  0.4423  0.9112  1.0
  O  O5  4  0.0000  0.0747  0.2500  1.0
]