The material structure described by K5Nb16(O5F2)4 crystallizes in the tetragonal I4mm space group. There are three inequivalent K sites. In the first K site, K(1) is bonded in a 9-coordinate geometry to four equivalent O(1), one F(1), two equivalent F(3), and two equivalent F(4) atoms. In the second K site, K(2) is bonded in a 9-coordinate geometry to four equivalent O(2); one F(2); and four equivalent F(5,6) atoms. In the third K site, K(3) is bonded in a 9-coordinate geometry to four equivalent O(3), one F(4), and four equivalent F(1) atoms. There are seven inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to four equivalent O(1) and one F(3) atom to form corner-sharing NbO4F square pyramids. In the second Nb site, Nb(2) is bonded to four equivalent O(1) and one F(4) atom to form corner-sharing NbO4F square pyramids. In the third Nb site, Nb(3,4) is bonded to four equivalent O(2) and one F(5,6) atom to form corner-sharing NbO4F square pyramids. In the fourth Nb site, Nb(5) is bonded in a rectangular see-saw-like geometry to one O(3), one O(4), one O(5), and one O(6) atom. In the fifth Nb site, Nb(6) is bonded to four equivalent O(3) and one F(1) atom to form corner-sharing NbO4F square pyramids. In the sixth Nb site, Nb(7) is bonded to four equivalent O(4) and one F(2) atom to form corner-sharing NbO4F square pyramids. In the seventh Nb site, Nb(8) is bonded in a square co-planar geometry to one O(1), one O(2), and two equivalent O(7) atoms. There are seven 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(1), one Nb(2), and one Nb(8) atom. In the second O site, O(2) is bonded in a distorted T-shaped geometry to two equivalent K(2); one Nb(8); and two equivalent Nb(3,4) atoms. In the third O site, O(3) is bonded in a distorted rectangular see-saw-like geometry to one K(3), one Nb(5), and two equivalent Nb(6) atoms. In the fourth O site, O(4) is bonded in a T-shaped geometry to one Nb(5) and two equivalent Nb(7) atoms. In the fifth O site, O(5) is bonded in a rectangular see-saw-like geometry to four equivalent Nb(5) atoms. In the sixth O site, O(6) is bonded in a rectangular see-saw-like geometry to four equivalent Nb(5) atoms. In the seventh O site, O(7) is bonded in a square co-planar geometry to four equivalent Nb(8) atoms. There are five inequivalent F sites. In the first F site, F(1) is bonded in a distorted square co-planar geometry to one K(1), two equivalent K(3), and one Nb(6) atom. In the second F site, F(2) is bonded in a linear geometry to one K(2) and one Nb(7) atom. In the third F site, F(3) is bonded to four equivalent K(1) and one Nb(1) atom to form distorted FK4Nb square pyramids that share corners with four equivalent F(3)K4Nb square pyramids and edges with four equivalent F(4)K5Nb octahedra. In the fourth F site, F(4) is bonded to one K(3), four equivalent K(1), and one Nb(2) atom to form FK5Nb octahedra that share corners with four equivalent F(4)K5Nb octahedra and edges with four equivalent F(3)K4Nb square pyramids. The corner-sharing octahedral tilt angles are 1°. In the fifth F site, F(5,6) is bonded to four equivalent K(2) and one Nb(3,4) atom to form a mixture of distorted corner and edge-sharing FK4Nb square pyramids. is represented by the Crystallographic Information File (CIF) [CIF]
data_K5Nb16(O5F2)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   22.554
_cell_length_b   22.554
_cell_length_c   22.554
_cell_angle_alpha   164.934
_cell_angle_beta   164.934
_cell_angle_gamma   21.369
_symmetry_Int_Tables_number   1
_cell_volume   775.059
_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  0.346  0.846  0.500  1.0
  K  K1  1  0.846  0.346  0.500  1.0
  K  K2  1  0.152  0.652  0.500  1.0
  K  K3  1  0.652  0.152  0.500  1.0
  K  K4  1  0.407  0.407  0.000  1.0
  Nb  Nb5  1  0.796  0.796  0.000  1.0
  Nb  Nb6  1  0.296  0.296  0.000  1.0
  Nb  Nb7  1  0.703  0.703  0.000  1.0
  Nb  Nb8  1  0.203  0.203  0.000  1.0
  Nb  Nb9  1  0.750  0.250  0.000  1.0
  Nb  Nb10  1  0.250  0.750  0.000  1.0
  Nb  Nb11  1  0.750  0.750  0.500  1.0
  Nb  Nb12  1  0.250  0.250  0.500  1.0
  Nb  Nb13  1  0.453  0.953  0.500  1.0
  Nb  Nb14  1  0.953  0.453  0.500  1.0
  Nb  Nb15  1  0.050  0.550  0.500  1.0
  Nb  Nb16  1  0.550  0.050  0.500  1.0
  Nb  Nb17  1  0.000  0.500  0.000  1.0
  Nb  Nb18  1  0.500  0.000  0.000  1.0
  Nb  Nb19  1  0.000  0.000  0.500  1.0
  Nb  Nb20  1  0.500  0.500  0.500  1.0
  O  O21  1  0.048  0.548  0.000  1.0
  O  O22  1  0.548  0.048  0.000  1.0
  O  O23  1  0.048  0.048  0.500  1.0
  O  O24  1  0.548  0.548  0.500  1.0
  O  O25  1  0.952  0.452  0.000  1.0
  O  O26  1  0.452  0.952  0.000  1.0
  O  O27  1  0.952  0.952  0.500  1.0
  O  O28  1  0.452  0.452  0.500  1.0
  O  O29  1  0.205  0.205  0.506  1.0
  O  O30  1  0.699  0.699  0.494  1.0
  O  O31  1  0.205  0.699  0.000  1.0
  O  O32  1  0.699  0.205  0.000  1.0
  O  O33  1  0.797  0.797  0.500  1.0
  O  O34  1  0.298  0.298  0.500  1.0
  O  O35  1  0.797  0.298  0.000  1.0
  O  O36  1  0.298  0.797  0.000  1.0
  O  O37  1  0.500  0.500  0.000  1.0
  O  O38  1  0.000  0.000  0.000  1.0
  O  O39  1  0.250  0.750  0.500  1.0
  O  O40  1  0.750  0.250  0.500  1.0
  F  F41  1  0.405  0.905  0.500  1.0
  F  F42  1  0.905  0.405  0.500  1.0
  F  F43  1  0.095  0.595  0.500  1.0
  F  F44  1  0.595  0.095  0.500  1.0
  F  F45  1  0.844  0.844  0.000  1.0
  F  F46  1  0.346  0.346  0.000  1.0
  F  F47  1  0.656  0.656  0.000  1.0
  F  F48  1  0.156  0.156  0.000  1.0
[/CIF]
.
The material structure described by K5Nb16(O5F2)4 crystallizes in the tetragonal I4mm space group. There are three inequivalent K sites. In the first K site, K(1) is bonded in a 9-coordinate geometry to four equivalent O(1), one F(1), two equivalent F(3), and two equivalent F(4) atoms. In the second K site, K(2) is bonded in a 9-coordinate geometry to four equivalent O(2); one F(2); and four equivalent F(5,6) atoms. In the third K site, K(3) is bonded in a 9-coordinate geometry to four equivalent O(3), one F(4), and four equivalent F(1) atoms. There are seven inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to four equivalent O(1) and one F(3) atom to form corner-sharing NbO4F square pyramids. In the second Nb site, Nb(2) is bonded to four equivalent O(1) and one F(4) atom to form corner-sharing NbO4F square pyramids. In the third Nb site, Nb(3,4) is bonded to four equivalent O(2) and one F(5,6) atom to form corner-sharing NbO4F square pyramids. In the fourth Nb site, Nb(5) is bonded in a rectangular see-saw-like geometry to one O(3), one O(4), one O(5), and one O(6) atom. In the fifth Nb site, Nb(6) is bonded to four equivalent O(3) and one F(1) atom to form corner-sharing NbO4F square pyramids. In the sixth Nb site, Nb(7) is bonded to four equivalent O(4) and one F(2) atom to form corner-sharing NbO4F square pyramids. In the seventh Nb site, Nb(8) is bonded in a square co-planar geometry to one O(1), one O(2), and two equivalent O(7) atoms. There are seven 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(1), one Nb(2), and one Nb(8) atom. In the second O site, O(2) is bonded in a distorted T-shaped geometry to two equivalent K(2); one Nb(8); and two equivalent Nb(3,4) atoms. In the third O site, O(3) is bonded in a distorted rectangular see-saw-like geometry to one K(3), one Nb(5), and two equivalent Nb(6) atoms. In the fourth O site, O(4) is bonded in a T-shaped geometry to one Nb(5) and two equivalent Nb(7) atoms. In the fifth O site, O(5) is bonded in a rectangular see-saw-like geometry to four equivalent Nb(5) atoms. In the sixth O site, O(6) is bonded in a rectangular see-saw-like geometry to four equivalent Nb(5) atoms. In the seventh O site, O(7) is bonded in a square co-planar geometry to four equivalent Nb(8) atoms. There are five inequivalent F sites. In the first F site, F(1) is bonded in a distorted square co-planar geometry to one K(1), two equivalent K(3), and one Nb(6) atom. In the second F site, F(2) is bonded in a linear geometry to one K(2) and one Nb(7) atom. In the third F site, F(3) is bonded to four equivalent K(1) and one Nb(1) atom to form distorted FK4Nb square pyramids that share corners with four equivalent F(3)K4Nb square pyramids and edges with four equivalent F(4)K5Nb octahedra. In the fourth F site, F(4) is bonded to one K(3), four equivalent K(1), and one Nb(2) atom to form FK5Nb octahedra that share corners with four equivalent F(4)K5Nb octahedra and edges with four equivalent F(3)K4Nb square pyramids. The corner-sharing octahedral tilt angles are 1°. In the fifth F site, F(5,6) is bonded to four equivalent K(2) and one Nb(3,4) atom to form a mixture of distorted corner and edge-sharing FK4Nb square pyramids. is represented by the Crystallographic Information File (CIF) [CIF]
data_K5Nb16(O5F2)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   22.554
_cell_length_b   22.554
_cell_length_c   22.554
_cell_angle_alpha   164.934
_cell_angle_beta   164.934
_cell_angle_gamma   21.369
_symmetry_Int_Tables_number   1
_cell_volume   775.059
_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  0.346  0.846  0.500  1.0
  K  K1  1  0.846  0.346  0.500  1.0
  K  K2  1  0.152  0.652  0.500  1.0
  K  K3  1  0.652  0.152  0.500  1.0
  K  K4  1  0.407  0.407  0.000  1.0
  Nb  Nb5  1  0.796  0.796  0.000  1.0
  Nb  Nb6  1  0.296  0.296  0.000  1.0
  Nb  Nb7  1  0.703  0.703  0.000  1.0
  Nb  Nb8  1  0.203  0.203  0.000  1.0
  Nb  Nb9  1  0.750  0.250  0.000  1.0
  Nb  Nb10  1  0.250  0.750  0.000  1.0
  Nb  Nb11  1  0.750  0.750  0.500  1.0
  Nb  Nb12  1  0.250  0.250  0.500  1.0
  Nb  Nb13  1  0.453  0.953  0.500  1.0
  Nb  Nb14  1  0.953  0.453  0.500  1.0
  Nb  Nb15  1  0.050  0.550  0.500  1.0
  Nb  Nb16  1  0.550  0.050  0.500  1.0
  Nb  Nb17  1  0.000  0.500  0.000  1.0
  Nb  Nb18  1  0.500  0.000  0.000  1.0
  Nb  Nb19  1  0.000  0.000  0.500  1.0
  Nb  Nb20  1  0.500  0.500  0.500  1.0
  O  O21  1  0.048  0.548  0.000  1.0
  O  O22  1  0.548  0.048  0.000  1.0
  O  O23  1  0.048  0.048  0.500  1.0
  O  O24  1  0.548  0.548  0.500  1.0
  O  O25  1  0.952  0.452  0.000  1.0
  O  O26  1  0.452  0.952  0.000  1.0
  O  O27  1  0.952  0.952  0.500  1.0
  O  O28  1  0.452  0.452  0.500  1.0
  O  O29  1  0.205  0.205  0.506  1.0
  O  O30  1  0.699  0.699  0.494  1.0
  O  O31  1  0.205  0.699  0.000  1.0
  O  O32  1  0.699  0.205  0.000  1.0
  O  O33  1  0.797  0.797  0.500  1.0
  O  O34  1  0.298  0.298  0.500  1.0
  O  O35  1  0.797  0.298  0.000  1.0
  O  O36  1  0.298  0.797  0.000  1.0
  O  O37  1  0.500  0.500  0.000  1.0
  O  O38  1  0.000  0.000  0.000  1.0
  O  O39  1  0.250  0.750  0.500  1.0
  O  O40  1  0.750  0.250  0.500  1.0
  F  F41  1  0.405  0.905  0.500  1.0
  F  F42  1  0.905  0.405  0.500  1.0
  F  F43  1  0.095  0.595  0.500  1.0
  F  F44  1  0.595  0.095  0.500  1.0
  F  F45  1  0.844  0.844  0.000  1.0
  F  F46  1  0.346  0.346  0.000  1.0
  F  F47  1  0.656  0.656  0.000  1.0
  F  F48  1  0.156  0.156  0.000  1.0
[/CIF]
.