data_[K8Nb4O12]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  K  0.8200  2.2000  1.5200
  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 [5.9218]
_cell_length_b [10.2340]
_cell_length_c [6.4764]
_cell_angle_alpha [90.0000]
_cell_angle_beta [108.3177]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [12]
_chemical_formula_structural [K2NbO3]
_chemical_formula_sum '[K8 Nb4 O12]'
_cell_volume [372.6069]
_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
[
  K  K0  4  0.0000  0.3423  0.0000  1
  K  K1  2  0.0000  0.0000  0.0000  1
  K  K2  2  0.0000  0.5000  0.5000  1
  Nb  Nb3  4  0.0000  0.1673  0.5000  1
  O  O4  8  0.2386  0.1984  0.3174  1
  O  O5  4  0.1671  0.0000  0.6817  1
]