data_[K2Mg2Nb2]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  K  0.8200  2.2000  1.5200
  Mg  1.3100  1.5000  0.8600
  Nb  1.6000  1.4500  0.8200
]
_symmetry_space_group_name_H-M [P-1]
_cell_length_a [3.1413]
_cell_length_b [4.7254]
_cell_length_c [13.0256]
_cell_angle_alpha [89.4466]
_cell_angle_beta [83.5955]
_cell_angle_gamma [85.2264]
_symmetry_Int_Tables_number [2]
_chemical_formula_structural [KMgNb]
_chemical_formula_sum '[K2 Mg2 Nb2]'
_cell_volume [191.4798]
_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  0.1611  0.7489  0.1502  1
  Mg  Mg1  2  0.4302  0.7522  0.6519  1
  Nb  Nb2  2  0.0215  0.7494  0.4607  1
]