data_K3Nb
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.29
_cell_length_b   8.29
_cell_length_c   6.61
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   K3Nb
_chemical_formula_sum   'K6 Nb2'
_cell_volume   393.4
_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  1  0.09  0.27  0.65  1.0
  K  K1  1  0.2  0.27  0.65  1.0
  K  K2  1  0.15  0.64  0.65  1.0
  K  K3  1  0.06  0.91  0.96  1.0
  K  K4  1  0.94  0.91  0.96  1.0
  K  K5  1  0.0  0.54  0.96  1.0
  Nb  Nb6  1  0.15  0.39  0.96  1.0
  Nb  Nb7  1  0.0  0.79  0.65  1.0

data_K3Nb
_symmetry_space_group_name_H-M   P-1
_cell_length_a   6.61
_cell_length_b   8.29
_cell_length_c   8.29
_cell_angle_alpha   120.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   2
_chemical_formula_structural   K3Nb
_chemical_formula_sum   'K6 Nb2'
_cell_volume   393.4
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-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  0.35  0.02  0.18  1.0
  K  K1  2  0.35  0.07  0.55  1.0
  K  K2  2  0.35  0.13  0.18  1.0
  Nb  Nb3  2  0.35  0.93  0.7  1.0

K K K K K K Nb Nb
K3Nb crystallizes in the triclinic P-1 space group. The structure is zero-dimensional and consists of two K3Nb clusters. There are three inequivalent K sites. In the first K site, K(1) is bonded in an L-shaped geometry to one K(2) and one Nb(1) atom. The K(1)-K(2) bond length is 0.94 Å. The K(1)-Nb(1) bond length is 2.19 Å. In the second K site, K(2) is bonded in a distorted single-bond geometry to one K(1) atom. In the third K site, K(3) is bonded in a distorted single-bond geometry to one Nb(1) atom. The K(3)-Nb(1) bond length is 2.12 Å. Nb(1) is bonded in a distorted water-like geometry to one K(1) and one K(3) atom.