The material described by Cs2U4Nb4O23 crystallizes in the monoclinic Cm space group. There are two inequivalent Cs sites. In the first Cs site, Cs(1) is bonded in a body-centered cubic geometry to two equivalent O(5), two equivalent O(6), two equivalent O(7), and two equivalent O(8) atoms. In the second Cs site, Cs(2) is bonded in a body-centered cubic geometry to two equivalent O(5), two equivalent O(6), two equivalent O(7), and two equivalent O(8) atoms. There are two inequivalent U sites. In the first U site, U(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), one O(7), and one O(9) atom to form distorted UO7 pentagonal bipyramids that share  a cornercorner with one Nb(2)O6 octahedra,  a cornercorner with one Nb(1)O5 trigonal bipyramid,  an edgeedge with one Nb(2)O6 octahedra, edges with two equivalent U(2)O7 pentagonal bipyramids, and  an edgeedge with one Nb(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 38°. In the second U site, U(2) is bonded to one O(1), one O(10), one O(2), one O(3), one O(4), one O(6), and one O(8) atom to form distorted UO7 pentagonal bipyramids that share  a cornercorner with one Nb(2)O6 octahedra,  a cornercorner with one Nb(1)O5 trigonal bipyramid,  an edgeedge with one Nb(2)O6 octahedra, edges with two equivalent U(1)O7 pentagonal bipyramids, and  an edgeedge with one Nb(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 38°. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one O(1), one O(10), one O(11), one O(2), and one O(9) atom to form NbO5 trigonal bipyramids that share corners with two equivalent Nb(2)O6 octahedra,  a cornercorner with one U(1)O7 pentagonal bipyramid,  a cornercorner with one U(2)O7 pentagonal bipyramid,  a cornercorner with one Nb(1)O5 trigonal bipyramid,  an edgeedge with one U(1)O7 pentagonal bipyramid, and  an edgeedge with one U(2)O7 pentagonal bipyramid. The corner-sharing octahedral tilt angles are 33°. In the second Nb site, Nb(2) is bonded to one O(10), one O(12), one O(13), one O(3), one O(4), and one O(9) atom to form distorted NbO6 octahedra that share  a cornercorner with one U(1)O7 pentagonal bipyramid,  a cornercorner with one U(2)O7 pentagonal bipyramid, corners with two equivalent Nb(1)O5 trigonal bipyramids,  an edgeedge with one Nb(2)O6 octahedra,  an edgeedge with one U(1)O7 pentagonal bipyramid, and  an edgeedge with one U(2)O7 pentagonal bipyramid. There are thirteen inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one U(1), one U(2), and one Nb(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one U(1), one U(2), and one Nb(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one U(1), one U(2), and one Nb(2) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one U(1), one U(2), and one Nb(2) atom. In the fifth O site, O(5) is bonded in a single-bond geometry to one Cs(1), one Cs(2), and one U(1) atom. In the sixth O site, O(6) is bonded in a single-bond geometry to one Cs(1), one Cs(2), and one U(2) atom. In the seventh O site, O(7) is bonded in a single-bond geometry to one Cs(1), one Cs(2), and one U(1) atom. In the eighth O site, O(8) is bonded in a single-bond geometry to one Cs(1), one Cs(2), and one U(2) atom. In the ninth O site, O(9) is bonded in a 3-coordinate geometry to one U(1), one Nb(1), and one Nb(2) atom. In the tenth O site, O(10) is bonded in a 3-coordinate geometry to one U(2), one Nb(1), and one Nb(2) atom. In the eleventh O site, O(11) is bonded in a linear geometry to two equivalent Nb(1) atoms. In the twelfth O site, O(12) is bonded in a water-like geometry to two equivalent Nb(2) atoms. In the thirteenth O site, O(13) is bonded in a water-like geometry to two equivalent Nb(2) atoms. is represented by the CIF card [CIF]
data_Cs2U4Nb4O23
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.703
_cell_length_b   8.808
_cell_length_c   8.808
_cell_angle_alpha   103.810
_cell_angle_beta   90.209
_cell_angle_gamma   90.209
_symmetry_Int_Tables_number   1
_cell_volume   580.319
_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
  Cs  Cs0  1  0.501  0.998  0.998  1.0
  Cs  Cs1  1  0.000  0.006  0.006  1.0
  U  U2  1  0.241  0.027  0.510  1.0
  U  U3  1  0.762  0.494  0.960  1.0
  U  U4  1  0.762  0.960  0.494  1.0
  U  U5  1  0.241  0.510  0.027  1.0
  Nb  Nb6  1  0.502  0.358  0.631  1.0
  Nb  Nb7  1  0.002  0.383  0.605  1.0
  Nb  Nb8  1  0.502  0.631  0.358  1.0
  Nb  Nb9  1  0.002  0.605  0.383  1.0
  O  O10  1  0.538  0.142  0.562  1.0
  O  O11  1  0.465  0.453  0.843  1.0
  O  O12  1  0.969  0.149  0.548  1.0
  O  O13  1  0.033  0.448  0.841  1.0
  O  O14  1  0.465  0.843  0.453  1.0
  O  O15  1  0.538  0.562  0.142  1.0
  O  O16  1  0.033  0.841  0.448  1.0
  O  O17  1  0.969  0.548  0.149  1.0
  O  O18  1  0.250  0.044  0.309  1.0
  O  O19  1  0.763  0.695  0.943  1.0
  O  O20  1  0.763  0.943  0.695  1.0
  O  O21  1  0.250  0.309  0.044  1.0
  O  O22  1  0.244  0.013  0.713  1.0
  O  O23  1  0.749  0.292  0.977  1.0
  O  O24  1  0.749  0.977  0.292  1.0
  O  O25  1  0.244  0.713  0.013  1.0
  O  O26  1  0.250  0.306  0.591  1.0
  O  O27  1  0.753  0.405  0.681  1.0
  O  O28  1  0.753  0.681  0.405  1.0
  O  O29  1  0.250  0.591  0.306  1.0
  O  O30  1  0.504  0.477  0.477  1.0
  O  O31  1  0.089  0.590  0.590  1.0
  O  O32  1  0.920  0.396  0.396  1.0
[/CIF]
.
The material described by Cs2U4Nb4O23 crystallizes in the monoclinic Cm space group. There are two inequivalent Cs sites. In the first Cs site, Cs(1) is bonded in a body-centered cubic geometry to two equivalent O(5), two equivalent O(6), two equivalent O(7), and two equivalent O(8) atoms. In the second Cs site, Cs(2) is bonded in a body-centered cubic geometry to two equivalent O(5), two equivalent O(6), two equivalent O(7), and two equivalent O(8) atoms. There are two inequivalent U sites. In the first U site, U(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), one O(7), and one O(9) atom to form distorted UO7 pentagonal bipyramids that share  a cornercorner with one Nb(2)O6 octahedra,  a cornercorner with one Nb(1)O5 trigonal bipyramid,  an edgeedge with one Nb(2)O6 octahedra, edges with two equivalent U(2)O7 pentagonal bipyramids, and  an edgeedge with one Nb(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 38°. In the second U site, U(2) is bonded to one O(1), one O(10), one O(2), one O(3), one O(4), one O(6), and one O(8) atom to form distorted UO7 pentagonal bipyramids that share  a cornercorner with one Nb(2)O6 octahedra,  a cornercorner with one Nb(1)O5 trigonal bipyramid,  an edgeedge with one Nb(2)O6 octahedra, edges with two equivalent U(1)O7 pentagonal bipyramids, and  an edgeedge with one Nb(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 38°. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one O(1), one O(10), one O(11), one O(2), and one O(9) atom to form NbO5 trigonal bipyramids that share corners with two equivalent Nb(2)O6 octahedra,  a cornercorner with one U(1)O7 pentagonal bipyramid,  a cornercorner with one U(2)O7 pentagonal bipyramid,  a cornercorner with one Nb(1)O5 trigonal bipyramid,  an edgeedge with one U(1)O7 pentagonal bipyramid, and  an edgeedge with one U(2)O7 pentagonal bipyramid. The corner-sharing octahedral tilt angles are 33°. In the second Nb site, Nb(2) is bonded to one O(10), one O(12), one O(13), one O(3), one O(4), and one O(9) atom to form distorted NbO6 octahedra that share  a cornercorner with one U(1)O7 pentagonal bipyramid,  a cornercorner with one U(2)O7 pentagonal bipyramid, corners with two equivalent Nb(1)O5 trigonal bipyramids,  an edgeedge with one Nb(2)O6 octahedra,  an edgeedge with one U(1)O7 pentagonal bipyramid, and  an edgeedge with one U(2)O7 pentagonal bipyramid. There are thirteen inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one U(1), one U(2), and one Nb(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one U(1), one U(2), and one Nb(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one U(1), one U(2), and one Nb(2) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one U(1), one U(2), and one Nb(2) atom. In the fifth O site, O(5) is bonded in a single-bond geometry to one Cs(1), one Cs(2), and one U(1) atom. In the sixth O site, O(6) is bonded in a single-bond geometry to one Cs(1), one Cs(2), and one U(2) atom. In the seventh O site, O(7) is bonded in a single-bond geometry to one Cs(1), one Cs(2), and one U(1) atom. In the eighth O site, O(8) is bonded in a single-bond geometry to one Cs(1), one Cs(2), and one U(2) atom. In the ninth O site, O(9) is bonded in a 3-coordinate geometry to one U(1), one Nb(1), and one Nb(2) atom. In the tenth O site, O(10) is bonded in a 3-coordinate geometry to one U(2), one Nb(1), and one Nb(2) atom. In the eleventh O site, O(11) is bonded in a linear geometry to two equivalent Nb(1) atoms. In the twelfth O site, O(12) is bonded in a water-like geometry to two equivalent Nb(2) atoms. In the thirteenth O site, O(13) is bonded in a water-like geometry to two equivalent Nb(2) atoms. is represented by the CIF card [CIF]
data_Cs2U4Nb4O23
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.703
_cell_length_b   8.808
_cell_length_c   8.808
_cell_angle_alpha   103.810
_cell_angle_beta   90.209
_cell_angle_gamma   90.209
_symmetry_Int_Tables_number   1
_cell_volume   580.319
_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
  Cs  Cs0  1  0.501  0.998  0.998  1.0
  Cs  Cs1  1  0.000  0.006  0.006  1.0
  U  U2  1  0.241  0.027  0.510  1.0
  U  U3  1  0.762  0.494  0.960  1.0
  U  U4  1  0.762  0.960  0.494  1.0
  U  U5  1  0.241  0.510  0.027  1.0
  Nb  Nb6  1  0.502  0.358  0.631  1.0
  Nb  Nb7  1  0.002  0.383  0.605  1.0
  Nb  Nb8  1  0.502  0.631  0.358  1.0
  Nb  Nb9  1  0.002  0.605  0.383  1.0
  O  O10  1  0.538  0.142  0.562  1.0
  O  O11  1  0.465  0.453  0.843  1.0
  O  O12  1  0.969  0.149  0.548  1.0
  O  O13  1  0.033  0.448  0.841  1.0
  O  O14  1  0.465  0.843  0.453  1.0
  O  O15  1  0.538  0.562  0.142  1.0
  O  O16  1  0.033  0.841  0.448  1.0
  O  O17  1  0.969  0.548  0.149  1.0
  O  O18  1  0.250  0.044  0.309  1.0
  O  O19  1  0.763  0.695  0.943  1.0
  O  O20  1  0.763  0.943  0.695  1.0
  O  O21  1  0.250  0.309  0.044  1.0
  O  O22  1  0.244  0.013  0.713  1.0
  O  O23  1  0.749  0.292  0.977  1.0
  O  O24  1  0.749  0.977  0.292  1.0
  O  O25  1  0.244  0.713  0.013  1.0
  O  O26  1  0.250  0.306  0.591  1.0
  O  O27  1  0.753  0.405  0.681  1.0
  O  O28  1  0.753  0.681  0.405  1.0
  O  O29  1  0.250  0.591  0.306  1.0
  O  O30  1  0.504  0.477  0.477  1.0
  O  O31  1  0.089  0.590  0.590  1.0
  O  O32  1  0.920  0.396  0.396  1.0
[/CIF]
.