USeO6 crystallizes in the monoclinic P2_1/c space group. U(1) is bonded to one O(2), one O(3), one O(4), one O(5), one O(6), and two equivalent O(1) atoms to form distorted UO7 pentagonal bipyramids that share corners with two equivalent U(1)O7 pentagonal bipyramids and corners with four equivalent Se(1)O4 tetrahedra. Se(1) is bonded to one O(2), one O(4), one O(5), and one O(6) atom to form SeO4 tetrahedra that share corners with four equivalent U(1)O7 pentagonal bipyramids. There are six inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 150 degrees geometry to two equivalent U(1) atoms. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one U(1) and one Se(1) atom. In the third O site, O(3) is bonded in a single-bond geometry to one U(1) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one U(1) and one Se(1) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one U(1) and one Se(1) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one U(1) and one Se(1) atom.
USeO6 crystallizes in the monoclinic P2_1/c space group. U(1) is bonded to one O(2), one O(3), one O(4), one O(5), one O(6), and two equivalent O(1) atoms to form distorted UO7 pentagonal bipyramids that share corners with two equivalent U(1)O7 pentagonal bipyramids and corners with four equivalent Se(1)O4 tetrahedra. The U(1)-O(2) bond length is 2.36 Å. The U(1)-O(3) bond length is 1.78 Å. The U(1)-O(4) bond length is 2.37 Å. The U(1)-O(5) bond length is 2.30 Å. The U(1)-O(6) bond length is 2.33 Å. There is one shorter (1.84 Å) and one longer (2.42 Å) U(1)-O(1) bond length. Se(1) is bonded to one O(2), one O(4), one O(5), and one O(6) atom to form SeO4 tetrahedra that share corners with four equivalent U(1)O7 pentagonal bipyramids. The Se(1)-O(2) bond length is 1.65 Å. The Se(1)-O(4) bond length is 1.65 Å. The Se(1)-O(5) bond length is 1.64 Å. The Se(1)-O(6) bond length is 1.64 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 150 degrees geometry to two equivalent U(1) atoms. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one U(1) and one Se(1) atom. In the third O site, O(3) is bonded in a single-bond geometry to one U(1) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one U(1) and one Se(1) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one U(1) and one Se(1) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one U(1) and one Se(1) atom.