data_KNb2Fe
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   2.87
_cell_length_b   2.87
_cell_length_c   10.13
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   94.94
_symmetry_Int_Tables_number   1
_chemical_formula_structural   KNb2Fe
_chemical_formula_sum   'K1 Nb2 Fe1'
_cell_volume   83.12
_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  K1  1  0.0  0.0  0.0  1.0
  Nb  Nb2  1  0.94  0.0  0.4  1.0
  Nb  Nb3  1  0.94  0.0  0.73  1.0
  Fe  Fe0  1  0.0  0.0  0.07  1.0

data_KNb2Fe
_symmetry_space_group_name_H-M   P1
_cell_length_a   2.87
_cell_length_b   2.87
_cell_length_c   10.13
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   94.94
_symmetry_Int_Tables_number   1
_chemical_formula_structural   KNb2Fe
_chemical_formula_sum   'K1 Nb2 Fe1'
_cell_volume   83.12
_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  0.94  0.0  0.4  1.0
  Nb  Nb2  1  0.94  0.0  0.73  1.0
  Fe  Fe3  1  0.0  0.0  0.07  1.0

K Nb Nb Fe
KNb2Fe crystallizes in the triclinic P1 space group. K(1) is bonded in a single-bond geometry to one Nb(2) and one Fe(1) atom. The K(1)-Nb(2) bond length is 2.75 Å. The K(1)-Fe(1) bond length is 0.68 Å. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one Nb(2), four equivalent Nb(1), and one Fe(1) atom to form a mixture of corner and edge-sharing NbNb5Fe octahedra. The corner-sharing octahedra are not tilted. The Nb(1)-Nb(2) bond length is 3.29 Å. All Nb(1)-Nb(1) bond lengths are 2.87 Å. The Nb(1)-Fe(1) bond length is 3.43 Å. In the second Nb site, Nb(2) is bonded in a distorted single-bond geometry to one K(1) and one Nb(1) atom. Fe(1) is bonded in a single-bond geometry to one K(1) and one Nb(1) atom.