The structure described by KNb4O5F crystallizes in the tetragonal P4/mmm space group. K(1) is bonded to eight equivalent O(1) and four equivalent F(1) atoms to form KO8F4 cuboctahedra that share corners with four equivalent K(1)O8F4 cuboctahedra, faces with four equivalent K(1)O8F4 cuboctahedra, and faces with eight equivalent Nb(1)O4F square pyramids. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to four equivalent O(1) and one F(1) atom to form NbO4F square pyramids that share corners with five equivalent Nb(1)O4F square pyramids and faces with four equivalent K(1)O8F4 cuboctahedra. In the second Nb site, Nb(2) is bonded in a square co-planar geometry to two equivalent O(1) and two equivalent O(2) atoms. There are two inequivalent O sites. In the first O site, O(1) is bonded in a distorted T-shaped geometry to two equivalent K(1), one Nb(2), and two equivalent Nb(1) atoms. In the second O site, O(2) is bonded in a square co-planar geometry to four equivalent Nb(2) atoms. F(1) is bonded to four equivalent K(1) and two equivalent Nb(1) atoms to form a mixture of distorted corner and edge-sharing FK4Nb2 octahedra. The corner-sharing octahedra are not tilted. is represented by the CIF file [CIF]
data_KNb4O5F
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.195
_cell_length_b   4.195
_cell_length_c   8.425
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   148.242
_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  0.000  0.000  0.500  1.0
  Nb  Nb1  1  0.500  0.500  0.238  1.0
  Nb  Nb2  1  0.500  0.500  0.762  1.0
  Nb  Nb3  1  0.500  0.000  0.000  1.0
  Nb  Nb4  1  0.000  0.500  0.000  1.0
  O  O5  1  0.000  0.500  0.251  1.0
  O  O6  1  0.000  0.500  0.749  1.0
  O  O7  1  0.500  0.000  0.251  1.0
  O  O8  1  0.000  0.000  0.000  1.0
  O  O9  1  0.500  0.000  0.749  1.0
  F  F10  1  0.500  0.500  0.500  1.0
[/CIF]
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The structure described by KNb4O5F crystallizes in the tetragonal P4/mmm space group. K(1) is bonded to eight equivalent O(1) and four equivalent F(1) atoms to form KO8F4 cuboctahedra that share corners with four equivalent K(1)O8F4 cuboctahedra, faces with four equivalent K(1)O8F4 cuboctahedra, and faces with eight equivalent Nb(1)O4F square pyramids. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to four equivalent O(1) and one F(1) atom to form NbO4F square pyramids that share corners with five equivalent Nb(1)O4F square pyramids and faces with four equivalent K(1)O8F4 cuboctahedra. In the second Nb site, Nb(2) is bonded in a square co-planar geometry to two equivalent O(1) and two equivalent O(2) atoms. There are two inequivalent O sites. In the first O site, O(1) is bonded in a distorted T-shaped geometry to two equivalent K(1), one Nb(2), and two equivalent Nb(1) atoms. In the second O site, O(2) is bonded in a square co-planar geometry to four equivalent Nb(2) atoms. F(1) is bonded to four equivalent K(1) and two equivalent Nb(1) atoms to form a mixture of distorted corner and edge-sharing FK4Nb2 octahedra. The corner-sharing octahedra are not tilted. is represented by the CIF file [CIF]
data_KNb4O5F
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.195
_cell_length_b   4.195
_cell_length_c   8.425
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   148.242
_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  0.000  0.000  0.500  1.0
  Nb  Nb1  1  0.500  0.500  0.238  1.0
  Nb  Nb2  1  0.500  0.500  0.762  1.0
  Nb  Nb3  1  0.500  0.000  0.000  1.0
  Nb  Nb4  1  0.000  0.500  0.000  1.0
  O  O5  1  0.000  0.500  0.251  1.0
  O  O6  1  0.000  0.500  0.749  1.0
  O  O7  1  0.500  0.000  0.251  1.0
  O  O8  1  0.000  0.000  0.000  1.0
  O  O9  1  0.500  0.000  0.749  1.0
  F  F10  1  0.500  0.500  0.500  1.0
[/CIF]
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