CeMg crystallizes in the trigonal P-3m1 space group. Mg(1) is bonded to nine equivalent Mg(1) and three equivalent Ce(1) atoms to form MgCe3Mg9 cuboctahedra that share corners with six equivalent Mg(1)Ce3Mg9 cuboctahedra, corners with twelve equivalent Ce(1)Ce9Mg3 cuboctahedra, edges with six equivalent Ce(1)Ce9Mg3 cuboctahedra, edges with twelve equivalent Mg(1)Ce3Mg9 cuboctahedra, faces with eight equivalent Ce(1)Ce9Mg3 cuboctahedra, and faces with twelve equivalent Mg(1)Ce3Mg9 cuboctahedra. Ce(1) is bonded to three equivalent Mg(1) and nine equivalent Ce(1) atoms to form distorted CeCe9Mg3 cuboctahedra that share corners with six equivalent Ce(1)Ce9Mg3 cuboctahedra, corners with twelve equivalent Mg(1)Ce3Mg9 cuboctahedra, edges with six equivalent Mg(1)Ce3Mg9 cuboctahedra, edges with twelve equivalent Ce(1)Ce9Mg3 cuboctahedra, faces with eight equivalent Mg(1)Ce3Mg9 cuboctahedra, and faces with twelve equivalent Ce(1)Ce9Mg3 cuboctahedra.
CeMg crystallizes in the trigonal P-3m1 space group. Mg(1) is bonded to nine equivalent Mg(1) and three equivalent Ce(1) atoms to form MgCe3Mg9 cuboctahedra that share corners with six equivalent Mg(1)Ce3Mg9 cuboctahedra, corners with twelve equivalent Ce(1)Ce9Mg3 cuboctahedra, edges with six equivalent Ce(1)Ce9Mg3 cuboctahedra, edges with twelve equivalent Mg(1)Ce3Mg9 cuboctahedra, faces with eight equivalent Ce(1)Ce9Mg3 cuboctahedra, and faces with twelve equivalent Mg(1)Ce3Mg9 cuboctahedra. There are six shorter (3.11 Å) and three longer (3.21 Å) Mg(1)-Mg(1) bond lengths. All Mg(1)-Ce(1) bond lengths are 3.46 Å. Ce(1) is bonded to three equivalent Mg(1) and nine equivalent Ce(1) atoms to form distorted CeCe9Mg3 cuboctahedra that share corners with six equivalent Ce(1)Ce9Mg3 cuboctahedra, corners with twelve equivalent Mg(1)Ce3Mg9 cuboctahedra, edges with six equivalent Mg(1)Ce3Mg9 cuboctahedra, edges with twelve equivalent Ce(1)Ce9Mg3 cuboctahedra, faces with eight equivalent Mg(1)Ce3Mg9 cuboctahedra, and faces with twelve equivalent Ce(1)Ce9Mg3 cuboctahedra. There are six shorter (3.11 Å) and three longer (3.64 Å) Ce(1)-Ce(1) bond lengths.