U5CeO12 is Fluorite-derived structured and crystallizes in the monoclinic C2/m space group. There are three inequivalent U sites. In the first U site, U(1) is bonded in a body-centered cubic geometry to two equivalent O(1), two equivalent O(2), and four equivalent O(4) atoms. In the second U site, U(2) is bonded in a body-centered cubic geometry to two equivalent O(3), two equivalent O(4), and four equivalent O(2) atoms. In the third U site, U(3) 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 two equivalent O(1), two equivalent O(3), and four equivalent O(4) atoms. There are four inequivalent O sites. In the first O site, O(1) is bonded to one U(3), two equivalent U(1), and one Ce(1) atom to form OCeU3 tetrahedra that share corners with two equivalent O(1)CeU3 tetrahedra, corners with two equivalent O(3)CeU3 tetrahedra, corners with four equivalent O(2)U4 tetrahedra, corners with eight equivalent O(4)CeU3 tetrahedra,  an edgeedge with one O(1)CeU3 tetrahedra,  an edgeedge with one O(3)CeU3 tetrahedra, edges with two equivalent O(4)CeU3 tetrahedra, and edges with two equivalent O(2)U4 tetrahedra. In the second O site, O(2) is bonded to one U(1), one U(3), and two equivalent U(2) atoms to form OU4 tetrahedra that share corners with two equivalent O(1)CeU3 tetrahedra, corners with four equivalent O(3)CeU3 tetrahedra, corners with four equivalent O(4)CeU3 tetrahedra, corners with six equivalent O(2)U4 tetrahedra,  an edgeedge with one O(1)CeU3 tetrahedra,  an edgeedge with one O(3)CeU3 tetrahedra, edges with two equivalent O(4)CeU3 tetrahedra, and edges with two equivalent O(2)U4 tetrahedra. In the third O site, O(3) is bonded to one U(3), two equivalent U(2), and one Ce(1) atom to form OCeU3 tetrahedra that share corners with two equivalent O(1)CeU3 tetrahedra, corners with two equivalent O(3)CeU3 tetrahedra, corners with four equivalent O(4)CeU3 tetrahedra, corners with eight equivalent O(2)U4 tetrahedra,  an edgeedge with one O(1)CeU3 tetrahedra,  an edgeedge with one O(3)CeU3 tetrahedra, edges with two equivalent O(4)CeU3 tetrahedra, and edges with two equivalent O(2)U4 tetrahedra. In the fourth O site, O(4) is bonded to one U(2), two equivalent U(1), and one Ce(1) atom to form OCeU3 tetrahedra that share corners with two equivalent O(3)CeU3 tetrahedra, corners with four equivalent O(1)CeU3 tetrahedra, corners with four equivalent O(2)U4 tetrahedra, corners with six equivalent O(4)CeU3 tetrahedra,  an edgeedge with one O(1)CeU3 tetrahedra,  an edgeedge with one O(3)CeU3 tetrahedra, edges with two equivalent O(4)CeU3 tetrahedra, and edges with two equivalent O(2)U4 tetrahedra.
U5CeO12 is Fluorite-derived structured and crystallizes in the monoclinic C2/m space group. There are three inequivalent U sites. In the first U site, U(1) is bonded in a body-centered cubic geometry to two equivalent O(1), two equivalent O(2), and four equivalent O(4) atoms. Both U(1)-O(1) bond lengths are 2.35 Å. Both U(1)-O(2) bond lengths are 2.42 Å. There are two shorter (2.31 Å) and two longer (2.37 Å) U(1)-O(4) bond lengths. In the second U site, U(2) is bonded in a body-centered cubic geometry to two equivalent O(3), two equivalent O(4), and four equivalent O(2) atoms. Both U(2)-O(3) bond lengths are 2.34 Å. Both U(2)-O(4) bond lengths are 2.38 Å. There are two shorter (2.28 Å) and two longer (2.38 Å) U(2)-O(2) bond lengths. In the third U site, U(3) 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(3)-O(1) bond lengths are 2.29 Å. Both U(3)-O(3) bond lengths are 2.34 Å. All U(3)-O(2) bond lengths are 2.36 Å. Ce(1) is bonded in a body-centered cubic geometry to two equivalent O(1), two equivalent O(3), and four equivalent O(4) atoms. Both Ce(1)-O(1) bond lengths are 2.47 Å. Both Ce(1)-O(3) bond lengths are 2.45 Å. All Ce(1)-O(4) bond lengths are 2.39 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded to one U(3), two equivalent U(1), and one Ce(1) atom to form OCeU3 tetrahedra that share corners with two equivalent O(1)CeU3 tetrahedra, corners with two equivalent O(3)CeU3 tetrahedra, corners with four equivalent O(2)U4 tetrahedra, corners with eight equivalent O(4)CeU3 tetrahedra,  an edgeedge with one O(1)CeU3 tetrahedra,  an edgeedge with one O(3)CeU3 tetrahedra, edges with two equivalent O(4)CeU3 tetrahedra, and edges with two equivalent O(2)U4 tetrahedra. In the second O site, O(2) is bonded to one U(1), one U(3), and two equivalent U(2) atoms to form OU4 tetrahedra that share corners with two equivalent O(1)CeU3 tetrahedra, corners with four equivalent O(3)CeU3 tetrahedra, corners with four equivalent O(4)CeU3 tetrahedra, corners with six equivalent O(2)U4 tetrahedra,  an edgeedge with one O(1)CeU3 tetrahedra,  an edgeedge with one O(3)CeU3 tetrahedra, edges with two equivalent O(4)CeU3 tetrahedra, and edges with two equivalent O(2)U4 tetrahedra. In the third O site, O(3) is bonded to one U(3), two equivalent U(2), and one Ce(1) atom to form OCeU3 tetrahedra that share corners with two equivalent O(1)CeU3 tetrahedra, corners with two equivalent O(3)CeU3 tetrahedra, corners with four equivalent O(4)CeU3 tetrahedra, corners with eight equivalent O(2)U4 tetrahedra,  an edgeedge with one O(1)CeU3 tetrahedra,  an edgeedge with one O(3)CeU3 tetrahedra, edges with two equivalent O(4)CeU3 tetrahedra, and edges with two equivalent O(2)U4 tetrahedra. In the fourth O site, O(4) is bonded to one U(2), two equivalent U(1), and one Ce(1) atom to form OCeU3 tetrahedra that share corners with two equivalent O(3)CeU3 tetrahedra, corners with four equivalent O(1)CeU3 tetrahedra, corners with four equivalent O(2)U4 tetrahedra, corners with six equivalent O(4)CeU3 tetrahedra,  an edgeedge with one O(1)CeU3 tetrahedra,  an edgeedge with one O(3)CeU3 tetrahedra, edges with two equivalent O(4)CeU3 tetrahedra, and edges with two equivalent O(2)U4 tetrahedra.