Li6CaCeO6 crystallizes in the trigonal P-31c space group. Li(1) is bonded to four equivalent O(1) atoms to form LiO4 tetrahedra that share corners with two equivalent Ca(1)O6 octahedra, corners with two equivalent Ce(1)O6 octahedra, corners with six equivalent Li(1)O4 tetrahedra,  an edgeedge with one Ca(1)O6 octahedra,  an edgeedge with one Ce(1)O6 octahedra, and edges with three equivalent Li(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 25-55°. Ca(1) is bonded to six equivalent O(1) atoms to form CaO6 octahedra that share corners with twelve equivalent Li(1)O4 tetrahedra, edges with three equivalent Ce(1)O6 octahedra, and edges with six equivalent Li(1)O4 tetrahedra. Ce(1) is bonded to six equivalent O(1) atoms to form CeO6 octahedra that share corners with twelve equivalent Li(1)O4 tetrahedra, edges with three equivalent Ca(1)O6 octahedra, and edges with six equivalent Li(1)O4 tetrahedra. O(1) is bonded to four equivalent Li(1), one Ca(1), and one Ce(1) atom to form a mixture of distorted edge and corner-sharing OLi4CaCe pentagonal pyramids.
Li6CaCeO6 crystallizes in the trigonal P-31c space group. Li(1) is bonded to four equivalent O(1) atoms to form LiO4 tetrahedra that share corners with two equivalent Ca(1)O6 octahedra, corners with two equivalent Ce(1)O6 octahedra, corners with six equivalent Li(1)O4 tetrahedra,  an edgeedge with one Ca(1)O6 octahedra,  an edgeedge with one Ce(1)O6 octahedra, and edges with three equivalent Li(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 25-55°. There are a spread of Li(1)-O(1) bond distances ranging from 1.98-2.12 Å. Ca(1) is bonded to six equivalent O(1) atoms to form CaO6 octahedra that share corners with twelve equivalent Li(1)O4 tetrahedra, edges with three equivalent Ce(1)O6 octahedra, and edges with six equivalent Li(1)O4 tetrahedra. All Ca(1)-O(1) bond lengths are 2.38 Å. Ce(1) is bonded to six equivalent O(1) atoms to form CeO6 octahedra that share corners with twelve equivalent Li(1)O4 tetrahedra, edges with three equivalent Ca(1)O6 octahedra, and edges with six equivalent Li(1)O4 tetrahedra. All Ce(1)-O(1) bond lengths are 2.28 Å. O(1) is bonded to four equivalent Li(1), one Ca(1), and one Ce(1) atom to form a mixture of distorted edge and corner-sharing OLi4CaCe pentagonal pyramids.