CsUNbO6 crystallizes in the monoclinic P2_1/c space group. Cs(1) is bonded in a 10-coordinate geometry to one O(3), one O(6), two equivalent O(1), three equivalent O(2), and three equivalent O(5) atoms. U(1) is bonded to one O(1), one O(2), one O(3), two equivalent O(4), and two equivalent O(6) atoms to form distorted UO7 pentagonal bipyramids that share corners with two equivalent U(1)O7 pentagonal bipyramids, corners with two equivalent Nb(1)O5 trigonal bipyramids,  an edgeedge with one U(1)O7 pentagonal bipyramid, and edges with two equivalent Nb(1)O5 trigonal bipyramids. Nb(1) is bonded to one O(4), one O(5), one O(6), and two equivalent O(3) atoms to form distorted NbO5 trigonal bipyramids that share corners with two equivalent U(1)O7 pentagonal bipyramids, edges with two equivalent U(1)O7 pentagonal bipyramids, and  an edgeedge with one Nb(1)O5 trigonal bipyramid. There are six inequivalent O sites. In the first O site, O(6) is bonded in a 3-coordinate geometry to one Cs(1), two equivalent U(1), and one Nb(1) atom. In the second O site, O(1) is bonded in a distorted single-bond geometry to two equivalent Cs(1) and one U(1) atom. In the third O site, O(2) is bonded in a single-bond geometry to three equivalent Cs(1) and one U(1) atom. In the fourth O site, O(3) is bonded in a 3-coordinate geometry to one Cs(1), one U(1), and two equivalent Nb(1) atoms. In the fifth O site, O(4) is bonded in a 3-coordinate geometry to two equivalent U(1) and one Nb(1) atom. In the sixth O site, O(5) is bonded in a distorted single-bond geometry to three equivalent Cs(1) and one Nb(1) atom.
CsUNbO6 crystallizes in the monoclinic P2_1/c space group. Cs(1) is bonded in a 10-coordinate geometry to one O(3), one O(6), two equivalent O(1), three equivalent O(2), and three equivalent O(5) atoms. The Cs(1)-O(3) bond length is 3.59 Å. The Cs(1)-O(6) bond length is 3.59 Å. There is one shorter (3.16 Å) and one longer (3.30 Å) Cs(1)-O(1) bond length. There are a spread of Cs(1)-O(2) bond distances ranging from 3.50-3.68 Å. There are a spread of Cs(1)-O(5) bond distances ranging from 3.12-3.37 Å. U(1) is bonded to one O(1), one O(2), one O(3), two equivalent O(4), and two equivalent O(6) atoms to form distorted UO7 pentagonal bipyramids that share corners with two equivalent U(1)O7 pentagonal bipyramids, corners with two equivalent Nb(1)O5 trigonal bipyramids,  an edgeedge with one U(1)O7 pentagonal bipyramid, and edges with two equivalent Nb(1)O5 trigonal bipyramids. The U(1)-O(1) bond length is 1.83 Å. The U(1)-O(2) bond length is 1.83 Å. The U(1)-O(3) bond length is 2.34 Å. There is one shorter (2.33 Å) and one longer (2.38 Å) U(1)-O(4) bond length. There is one shorter (2.39 Å) and one longer (2.49 Å) U(1)-O(6) bond length. Nb(1) is bonded to one O(4), one O(5), one O(6), and two equivalent O(3) atoms to form distorted NbO5 trigonal bipyramids that share corners with two equivalent U(1)O7 pentagonal bipyramids, edges with two equivalent U(1)O7 pentagonal bipyramids, and  an edgeedge with one Nb(1)O5 trigonal bipyramid. The Nb(1)-O(4) bond length is 1.95 Å. The Nb(1)-O(5) bond length is 1.79 Å. The Nb(1)-O(6) bond length is 1.96 Å. There is one shorter (2.04 Å) and one longer (2.08 Å) Nb(1)-O(3) bond length. There are six inequivalent O sites. In the first O site, O(6) is bonded in a 3-coordinate geometry to one Cs(1), two equivalent U(1), and one Nb(1) atom. In the second O site, O(1) is bonded in a distorted single-bond geometry to two equivalent Cs(1) and one U(1) atom. In the third O site, O(2) is bonded in a single-bond geometry to three equivalent Cs(1) and one U(1) atom. In the fourth O site, O(3) is bonded in a 3-coordinate geometry to one Cs(1), one U(1), and two equivalent Nb(1) atoms. In the fifth O site, O(4) is bonded in a 3-coordinate geometry to two equivalent U(1) and one Nb(1) atom. In the sixth O site, O(5) is bonded in a distorted single-bond geometry to three equivalent Cs(1) and one Nb(1) atom.