data_KNbCu2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   2.77
_cell_length_b   4.65
_cell_length_c   5.35
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   KNbCu2
_chemical_formula_sum   'K1 Nb1 Cu2'
_cell_volume   68.98
_cell_formula_units_Z   1
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  K2  1  0.0  0.0  0.0  1.0
  Nb  Nb3  1  0.0  0.32  0.67  1.0
  Cu  Cu0  1  0.39  0.32  0.0  1.0
  Cu  Cu1  1  0.39  0.0  0.67  1.0

data_KNbCu2
_symmetry_space_group_name_H-M   P1
_cell_length_a   2.77
_cell_length_b   4.65
_cell_length_c   5.35
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   KNbCu2
_chemical_formula_sum   'K1 Nb1 Cu2'
_cell_volume   68.98
_cell_formula_units_Z   1
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  1  0.0  0.0  0.0  1.0
  Nb  Nb1  1  0.0  0.32  0.67  1.0
  Cu  Cu2  1  0.39  0.0  0.67  1.0
  Cu  Cu3  1  0.39  0.32  0.0  1.0

K Nb Cu Cu
K Nb Cu Cu 0 2 - o o 0 2 o o o 0 3 o o - 0 1 o o - 1 3 - o o 1 3 o o o 1 2 o o + 2 3 o o - 