data_[K2Nb4As2O16]
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
  As  2.1800  1.1500  0.6600
  O  3.4400  0.6000  1.2600
]
_symmetry_space_group_name_H-M [C2/m]
_cell_length_a [9.2810]
_cell_length_b [5.5756]
_cell_length_c [8.5691]
_cell_angle_alpha [90.0000]
_cell_angle_beta [107.3297]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [12]
_chemical_formula_structural [KNb2AsO8]
_chemical_formula_sum '[K2 Nb4 As2 O16]'
_cell_volume [423.2975]
_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  0.0000  0.5000  0.5000  1
  Nb  Nb1  4  0.1952  0.5000  0.1753  1
  As  As2  2  0.0000  0.0000  0.0000  1
  O  O3  8  0.0602  0.2325  0.1605  1
  O  O4  4  0.1890  0.0000  0.6183  1
  O  O5  4  0.1921  0.0000  0.9779  1
]