Th4CeO10 is Fluorite-derived structured and crystallizes in the tetragonal I4/mmm space group. There are two inequivalent Th sites. In the first Th site, Th(1) is bonded in a body-centered cubic geometry to four equivalent O(1) and four equivalent O(2) atoms. In the second Th site, Th(2) is bonded in a body-centered cubic geometry to four equivalent O(1) and four equivalent O(3) atoms. Ce(1) is bonded in a body-centered cubic geometry to eight equivalent O(2) atoms. There are three inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Th(1) and two equivalent Th(2) atoms to form OTh4 tetrahedra that share corners with four equivalent O(1)Th4 tetrahedra, corners with six equivalent O(2)Ce2Th2 tetrahedra, corners with six equivalent O(3)Th4 tetrahedra,  an edgeedge with one O(2)Ce2Th2 tetrahedra,  an edgeedge with one O(3)Th4 tetrahedra, and edges with four equivalent O(1)Th4 tetrahedra. In the second O site, O(2) is bonded to two equivalent Th(1) and two equivalent Ce(1) atoms to form OCe2Th2 tetrahedra that share corners with six equivalent O(1)Th4 tetrahedra, corners with ten equivalent O(2)Ce2Th2 tetrahedra,  an edgeedge with one O(1)Th4 tetrahedra, and edges with five equivalent O(2)Ce2Th2 tetrahedra. In the third O site, O(3) is bonded to four equivalent Th(2) atoms to form a mixture of edge and corner-sharing OTh4 tetrahedra.
Th4CeO10 is Fluorite-derived structured and crystallizes in the tetragonal I4/mmm space group. There are two inequivalent Th sites. In the first Th site, Th(1) is bonded in a body-centered cubic geometry to four equivalent O(1) and four equivalent O(2) atoms. All Th(1)-O(1) bond lengths are 2.42 Å. All Th(1)-O(2) bond lengths are 2.41 Å. In the second Th site, Th(2) is bonded in a body-centered cubic geometry to four equivalent O(1) and four equivalent O(3) atoms. All Th(2)-O(1) bond lengths are 2.42 Å. All Th(2)-O(3) bond lengths are 2.42 Å. Ce(1) is bonded in a body-centered cubic geometry to eight equivalent O(2) atoms. All Ce(1)-O(2) bond lengths are 2.39 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Th(1) and two equivalent Th(2) atoms to form OTh4 tetrahedra that share corners with four equivalent O(1)Th4 tetrahedra, corners with six equivalent O(2)Ce2Th2 tetrahedra, corners with six equivalent O(3)Th4 tetrahedra,  an edgeedge with one O(2)Ce2Th2 tetrahedra,  an edgeedge with one O(3)Th4 tetrahedra, and edges with four equivalent O(1)Th4 tetrahedra. In the second O site, O(2) is bonded to two equivalent Th(1) and two equivalent Ce(1) atoms to form OCe2Th2 tetrahedra that share corners with six equivalent O(1)Th4 tetrahedra, corners with ten equivalent O(2)Ce2Th2 tetrahedra,  an edgeedge with one O(1)Th4 tetrahedra, and edges with five equivalent O(2)Ce2Th2 tetrahedra. In the third O site, O(3) is bonded to four equivalent Th(2) atoms to form a mixture of edge and corner-sharing OTh4 tetrahedra.