data_[K2Nb2O6]
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 [P2_1/m]
_cell_length_a [4.2027]
_cell_length_b [6.0284]
_cell_length_c [6.4955]
_cell_angle_alpha [90.0000]
_cell_angle_beta [104.2319]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [11]
_chemical_formula_structural [KNbO3]
_chemical_formula_sum '[K2 Nb2 O6]'
_cell_volume [159.5196]
_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
[
  K  K0  2  0.1871  0.7500  0.9094  1.0
  Nb  Nb1  2  0.4387  0.2500  0.5311  1.0
  O  O2  4  0.4152  0.0112  0.2869  1.0
  O  O3  2  0.0042  0.2500  0.5257  1.0
]