U2CeO6 is Fluorite-derived structured and crystallizes in the orthorhombic Immm space group. U(1) is bonded in a body-centered cubic geometry to two equivalent O(1), two equivalent O(3), and four equivalent O(2) atoms. Ce(1) is bonded in a body-centered cubic geometry to four equivalent O(1) and four equivalent O(3) atoms. There are three inequivalent O sites. In the first O site, O(1) is bonded to two equivalent U(1) and two equivalent Ce(1) atoms to form OCe2U2 tetrahedra that share corners with four equivalent O(3)Ce2U2 tetrahedra, corners with six equivalent O(1)Ce2U2 tetrahedra, corners with six equivalent O(2)U4 tetrahedra,  an edgeedge with one O(1)Ce2U2 tetrahedra,  an edgeedge with one O(2)U4 tetrahedra, and edges with four equivalent O(3)Ce2U2 tetrahedra. In the second O site, O(2) is bonded to four equivalent U(1) atoms to form OU4 tetrahedra that share corners with four equivalent O(2)U4 tetrahedra, corners with six equivalent O(1)Ce2U2 tetrahedra, corners with six equivalent O(3)Ce2U2 tetrahedra,  an edgeedge with one O(1)Ce2U2 tetrahedra,  an edgeedge with one O(3)Ce2U2 tetrahedra, and edges with four equivalent O(2)U4 tetrahedra. In the third O site, O(3) is bonded to two equivalent U(1) and two equivalent Ce(1) atoms to form OCe2U2 tetrahedra that share corners with four equivalent O(1)Ce2U2 tetrahedra, corners with six equivalent O(3)Ce2U2 tetrahedra, corners with six equivalent O(2)U4 tetrahedra,  an edgeedge with one O(3)Ce2U2 tetrahedra,  an edgeedge with one O(2)U4 tetrahedra, and edges with four equivalent O(1)Ce2U2 tetrahedra.
U2CeO6 is Fluorite-derived structured and crystallizes in the orthorhombic Immm space group. U(1) is bonded in a body-centered cubic geometry to two equivalent O(1), two equivalent O(3), and four equivalent O(2) atoms. Both U(1)-O(1) bond lengths are 2.31 Å. Both U(1)-O(3) bond lengths are 2.31 Å. There are two shorter (2.36 Å) and two longer (2.37 Å) U(1)-O(2) bond lengths. Ce(1) is bonded in a body-centered cubic geometry to four equivalent O(1) and four equivalent O(3) atoms. All Ce(1)-O(1) bond lengths are 2.40 Å. All Ce(1)-O(3) bond lengths are 2.40 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded to two equivalent U(1) and two equivalent Ce(1) atoms to form OCe2U2 tetrahedra that share corners with four equivalent O(3)Ce2U2 tetrahedra, corners with six equivalent O(1)Ce2U2 tetrahedra, corners with six equivalent O(2)U4 tetrahedra,  an edgeedge with one O(1)Ce2U2 tetrahedra,  an edgeedge with one O(2)U4 tetrahedra, and edges with four equivalent O(3)Ce2U2 tetrahedra. In the second O site, O(2) is bonded to four equivalent U(1) atoms to form OU4 tetrahedra that share corners with four equivalent O(2)U4 tetrahedra, corners with six equivalent O(1)Ce2U2 tetrahedra, corners with six equivalent O(3)Ce2U2 tetrahedra,  an edgeedge with one O(1)Ce2U2 tetrahedra,  an edgeedge with one O(3)Ce2U2 tetrahedra, and edges with four equivalent O(2)U4 tetrahedra. In the third O site, O(3) is bonded to two equivalent U(1) and two equivalent Ce(1) atoms to form OCe2U2 tetrahedra that share corners with four equivalent O(1)Ce2U2 tetrahedra, corners with six equivalent O(3)Ce2U2 tetrahedra, corners with six equivalent O(2)U4 tetrahedra,  an edgeedge with one O(3)Ce2U2 tetrahedra,  an edgeedge with one O(2)U4 tetrahedra, and edges with four equivalent O(1)Ce2U2 tetrahedra.