The material described by K5U2O4F9 crystallizes in the monoclinic C2/c space group. There are three inequivalent K sites. In the first K site, K(1) is bonded in a 8-coordinate geometry to one O(1), one O(2), one F(2), one F(3), two equivalent F(4), and two equivalent F(5) atoms. In the second K site, K(2) is bonded in a 8-coordinate geometry to one O(1), two equivalent O(2), one F(1), two equivalent F(2), and two equivalent F(3) atoms. In the third K site, K(3) is bonded to two equivalent O(1), two equivalent F(4), and two equivalent F(5) atoms to form KO2F4 octahedra that share corners with six equivalent U(1)O2F5 pentagonal bipyramids. U(1) is bonded to one O(1), one O(2), one F(1), one F(2), one F(3), one F(4), and one F(5) atom to form UO2F5 pentagonal bipyramids that share corners with three equivalent K(3)O2F4 octahedra and  a cornercorner with one U(1)O2F5 pentagonal bipyramid. The corner-sharing octahedral tilt angles range from 32-36°. There are two inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one K(1), one K(2), one K(3), and one U(1) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to one K(1), two equivalent K(2), and one U(1) atom. There are five inequivalent F sites. In the first F site, F(1) is bonded to two equivalent K(2) and two equivalent U(1) atoms to form a mixture of distorted corner and edge-sharing FK2U2 trigonal pyramids. In the second F site, F(2) is bonded in a distorted see-saw-like geometry to one K(1), two equivalent K(2), and one U(1) atom. In the third F site, F(3) is bonded to one K(1), two equivalent K(2), and one U(1) atom to form distorted FK3U trigonal pyramids that share corners with three equivalent F(4)K3U tetrahedra, corners with three equivalent F(5)K3U tetrahedra,  a cornercorner with one F(1)K2U2 trigonal pyramid,  an edgeedge with one F(1)K2U2 trigonal pyramid, and  an edgeedge with one F(3)K3U trigonal pyramid. In the fourth F site, F(4) is bonded to one K(3), two equivalent K(1), and one U(1) atom to form distorted FK3U tetrahedra that share  a cornercorner with one F(4)K3U tetrahedra, corners with three equivalent F(5)K3U tetrahedra,  a cornercorner with one F(1)K2U2 trigonal pyramid, corners with three equivalent F(3)K3U trigonal pyramids,  an edgeedge with one F(4)K3U tetrahedra, and edges with two equivalent F(5)K3U tetrahedra. In the fifth F site, F(5) is bonded to one K(3), two equivalent K(1), and one U(1) atom to form distorted FK3U tetrahedra that share corners with three equivalent F(4)K3U tetrahedra, corners with three equivalent F(5)K3U tetrahedra,  a cornercorner with one F(1)K2U2 trigonal pyramid, corners with three equivalent F(3)K3U trigonal pyramids, and edges with two equivalent F(4)K3U tetrahedra. is represented by the CIF file [CIF]
data_K5U2O4F9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.472
_cell_length_b   10.472
_cell_length_c   11.718
_cell_angle_alpha   78.821
_cell_angle_beta   78.821
_cell_angle_gamma   34.772
_symmetry_Int_Tables_number   1
_cell_volume   717.579
_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  0.422  0.940  0.867  1.0
  K  K1  1  0.770  0.276  0.081  1.0
  K  K2  1  0.230  0.724  0.919  1.0
  K  K3  1  0.578  0.060  0.133  1.0
  K  K4  1  0.940  0.422  0.367  1.0
  K  K5  1  0.724  0.230  0.419  1.0
  K  K6  1  0.000  0.500  0.000  1.0
  K  K7  1  0.276  0.770  0.581  1.0
  K  K8  1  0.060  0.578  0.633  1.0
  K  K9  1  0.500  0.000  0.500  1.0
  U  U10  1  0.370  0.855  0.216  1.0
  U  U11  1  0.630  0.145  0.784  1.0
  U  U12  1  0.855  0.370  0.716  1.0
  U  U13  1  0.145  0.630  0.284  1.0
  O  O14  1  0.340  0.372  0.850  1.0
  O  O15  1  0.372  0.340  0.350  1.0
  O  O16  1  0.628  0.660  0.650  1.0
  O  O17  1  0.079  0.081  0.280  1.0
  O  O18  1  0.660  0.628  0.150  1.0
  O  O19  1  0.081  0.079  0.780  1.0
  O  O20  1  0.921  0.919  0.720  1.0
  O  O21  1  0.919  0.921  0.220  1.0
  F  F22  1  0.588  0.412  0.750  1.0
  F  F23  1  0.763  0.104  0.939  1.0
  F  F24  1  0.341  0.478  0.112  1.0
  F  F25  1  0.698  0.908  0.918  1.0
  F  F26  1  0.412  0.588  0.250  1.0
  F  F27  1  0.404  0.002  0.302  1.0
  F  F28  1  0.908  0.698  0.418  1.0
  F  F29  1  0.092  0.302  0.582  1.0
  F  F30  1  0.896  0.237  0.561  1.0
  F  F31  1  0.104  0.763  0.439  1.0
  F  F32  1  0.478  0.341  0.612  1.0
  F  F33  1  0.522  0.659  0.388  1.0
  F  F34  1  0.596  0.998  0.698  1.0
  F  F35  1  0.302  0.092  0.082  1.0
  F  F36  1  0.659  0.522  0.888  1.0
  F  F37  1  0.237  0.896  0.061  1.0
  F  F38  1  0.998  0.596  0.198  1.0
  F  F39  1  0.002  0.404  0.802  1.0
[/CIF]
.
The material described by K5U2O4F9 crystallizes in the monoclinic C2/c space group. There are three inequivalent K sites. In the first K site, K(1) is bonded in a 8-coordinate geometry to one O(1), one O(2), one F(2), one F(3), two equivalent F(4), and two equivalent F(5) atoms. In the second K site, K(2) is bonded in a 8-coordinate geometry to one O(1), two equivalent O(2), one F(1), two equivalent F(2), and two equivalent F(3) atoms. In the third K site, K(3) is bonded to two equivalent O(1), two equivalent F(4), and two equivalent F(5) atoms to form KO2F4 octahedra that share corners with six equivalent U(1)O2F5 pentagonal bipyramids. U(1) is bonded to one O(1), one O(2), one F(1), one F(2), one F(3), one F(4), and one F(5) atom to form UO2F5 pentagonal bipyramids that share corners with three equivalent K(3)O2F4 octahedra and  a cornercorner with one U(1)O2F5 pentagonal bipyramid. The corner-sharing octahedral tilt angles range from 32-36°. There are two inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one K(1), one K(2), one K(3), and one U(1) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to one K(1), two equivalent K(2), and one U(1) atom. There are five inequivalent F sites. In the first F site, F(1) is bonded to two equivalent K(2) and two equivalent U(1) atoms to form a mixture of distorted corner and edge-sharing FK2U2 trigonal pyramids. In the second F site, F(2) is bonded in a distorted see-saw-like geometry to one K(1), two equivalent K(2), and one U(1) atom. In the third F site, F(3) is bonded to one K(1), two equivalent K(2), and one U(1) atom to form distorted FK3U trigonal pyramids that share corners with three equivalent F(4)K3U tetrahedra, corners with three equivalent F(5)K3U tetrahedra,  a cornercorner with one F(1)K2U2 trigonal pyramid,  an edgeedge with one F(1)K2U2 trigonal pyramid, and  an edgeedge with one F(3)K3U trigonal pyramid. In the fourth F site, F(4) is bonded to one K(3), two equivalent K(1), and one U(1) atom to form distorted FK3U tetrahedra that share  a cornercorner with one F(4)K3U tetrahedra, corners with three equivalent F(5)K3U tetrahedra,  a cornercorner with one F(1)K2U2 trigonal pyramid, corners with three equivalent F(3)K3U trigonal pyramids,  an edgeedge with one F(4)K3U tetrahedra, and edges with two equivalent F(5)K3U tetrahedra. In the fifth F site, F(5) is bonded to one K(3), two equivalent K(1), and one U(1) atom to form distorted FK3U tetrahedra that share corners with three equivalent F(4)K3U tetrahedra, corners with three equivalent F(5)K3U tetrahedra,  a cornercorner with one F(1)K2U2 trigonal pyramid, corners with three equivalent F(3)K3U trigonal pyramids, and edges with two equivalent F(4)K3U tetrahedra. is represented by the CIF file [CIF]
data_K5U2O4F9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.472
_cell_length_b   10.472
_cell_length_c   11.718
_cell_angle_alpha   78.821
_cell_angle_beta   78.821
_cell_angle_gamma   34.772
_symmetry_Int_Tables_number   1
_cell_volume   717.579
_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  0.422  0.940  0.867  1.0
  K  K1  1  0.770  0.276  0.081  1.0
  K  K2  1  0.230  0.724  0.919  1.0
  K  K3  1  0.578  0.060  0.133  1.0
  K  K4  1  0.940  0.422  0.367  1.0
  K  K5  1  0.724  0.230  0.419  1.0
  K  K6  1  0.000  0.500  0.000  1.0
  K  K7  1  0.276  0.770  0.581  1.0
  K  K8  1  0.060  0.578  0.633  1.0
  K  K9  1  0.500  0.000  0.500  1.0
  U  U10  1  0.370  0.855  0.216  1.0
  U  U11  1  0.630  0.145  0.784  1.0
  U  U12  1  0.855  0.370  0.716  1.0
  U  U13  1  0.145  0.630  0.284  1.0
  O  O14  1  0.340  0.372  0.850  1.0
  O  O15  1  0.372  0.340  0.350  1.0
  O  O16  1  0.628  0.660  0.650  1.0
  O  O17  1  0.079  0.081  0.280  1.0
  O  O18  1  0.660  0.628  0.150  1.0
  O  O19  1  0.081  0.079  0.780  1.0
  O  O20  1  0.921  0.919  0.720  1.0
  O  O21  1  0.919  0.921  0.220  1.0
  F  F22  1  0.588  0.412  0.750  1.0
  F  F23  1  0.763  0.104  0.939  1.0
  F  F24  1  0.341  0.478  0.112  1.0
  F  F25  1  0.698  0.908  0.918  1.0
  F  F26  1  0.412  0.588  0.250  1.0
  F  F27  1  0.404  0.002  0.302  1.0
  F  F28  1  0.908  0.698  0.418  1.0
  F  F29  1  0.092  0.302  0.582  1.0
  F  F30  1  0.896  0.237  0.561  1.0
  F  F31  1  0.104  0.763  0.439  1.0
  F  F32  1  0.478  0.341  0.612  1.0
  F  F33  1  0.522  0.659  0.388  1.0
  F  F34  1  0.596  0.998  0.698  1.0
  F  F35  1  0.302  0.092  0.082  1.0
  F  F36  1  0.659  0.522  0.888  1.0
  F  F37  1  0.237  0.896  0.061  1.0
  F  F38  1  0.998  0.596  0.198  1.0
  F  F39  1  0.002  0.404  0.802  1.0
[/CIF]
.