CeCo4Al crystallizes in the hexagonal P-6m2 space group. Ce(1) is bonded in a 18-coordinate geometry to three equivalent Co(1), twelve equivalent Co(2), and three equivalent Al(1) atoms. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to three equivalent Ce(1), six equivalent Co(2), and three equivalent Al(1) atoms to form CoCe3Al3Co6 cuboctahedra that share corners with nine equivalent Al(1)Ce3Co9 cuboctahedra, corners with twelve equivalent Co(2)Ce4Al2Co6 cuboctahedra, edges with six equivalent Co(1)Ce3Al3Co6 cuboctahedra, faces with two equivalent Co(1)Ce3Al3Co6 cuboctahedra, faces with three equivalent Al(1)Ce3Co9 cuboctahedra, and faces with eighteen equivalent Co(2)Ce4Al2Co6 cuboctahedra. In the second Co site, Co(2) is bonded to four equivalent Ce(1), two equivalent Co(1), four equivalent Co(2), and two equivalent Al(1) atoms to form distorted CoCe4Al2Co6 cuboctahedra that share corners with four equivalent Co(1)Ce3Al3Co6 cuboctahedra, corners with four equivalent Al(1)Ce3Co9 cuboctahedra, corners with sixteen equivalent Co(2)Ce4Al2Co6 cuboctahedra, edges with ten equivalent Co(2)Ce4Al2Co6 cuboctahedra, faces with six equivalent Co(1)Ce3Al3Co6 cuboctahedra, faces with six equivalent Al(1)Ce3Co9 cuboctahedra, and faces with ten equivalent Co(2)Ce4Al2Co6 cuboctahedra. Al(1) is bonded to three equivalent Ce(1), three equivalent Co(1), and six equivalent Co(2) atoms to form distorted AlCe3Co9 cuboctahedra that share corners with nine equivalent Co(1)Ce3Al3Co6 cuboctahedra, corners with twelve equivalent Co(2)Ce4Al2Co6 cuboctahedra, edges with six equivalent Al(1)Ce3Co9 cuboctahedra, faces with two equivalent Al(1)Ce3Co9 cuboctahedra, faces with three equivalent Co(1)Ce3Al3Co6 cuboctahedra, and faces with eighteen equivalent Co(2)Ce4Al2Co6 cuboctahedra.
CeCo4Al crystallizes in the hexagonal P-6m2 space group. Ce(1) is bonded in a 18-coordinate geometry to three equivalent Co(1), twelve equivalent Co(2), and three equivalent Al(1) atoms. All Ce(1)-Co(1) bond lengths are 2.94 Å. All Ce(1)-Co(2) bond lengths are 3.20 Å. All Ce(1)-Al(1) bond lengths are 2.94 Å. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to three equivalent Ce(1), six equivalent Co(2), and three equivalent Al(1) atoms to form CoCe3Al3Co6 cuboctahedra that share corners with nine equivalent Al(1)Ce3Co9 cuboctahedra, corners with twelve equivalent Co(2)Ce4Al2Co6 cuboctahedra, edges with six equivalent Co(1)Ce3Al3Co6 cuboctahedra, faces with two equivalent Co(1)Ce3Al3Co6 cuboctahedra, faces with three equivalent Al(1)Ce3Co9 cuboctahedra, and faces with eighteen equivalent Co(2)Ce4Al2Co6 cuboctahedra. All Co(1)-Co(2) bond lengths are 2.41 Å. All Co(1)-Al(1) bond lengths are 2.94 Å. In the second Co site, Co(2) is bonded to four equivalent Ce(1), two equivalent Co(1), four equivalent Co(2), and two equivalent Al(1) atoms to form distorted CoCe4Al2Co6 cuboctahedra that share corners with four equivalent Co(1)Ce3Al3Co6 cuboctahedra, corners with four equivalent Al(1)Ce3Co9 cuboctahedra, corners with sixteen equivalent Co(2)Ce4Al2Co6 cuboctahedra, edges with ten equivalent Co(2)Ce4Al2Co6 cuboctahedra, faces with six equivalent Co(1)Ce3Al3Co6 cuboctahedra, faces with six equivalent Al(1)Ce3Co9 cuboctahedra, and faces with ten equivalent Co(2)Ce4Al2Co6 cuboctahedra. There are two shorter (2.50 Å) and two longer (2.60 Å) Co(2)-Co(2) bond lengths. Both Co(2)-Al(1) bond lengths are 2.44 Å. Al(1) is bonded to three equivalent Ce(1), three equivalent Co(1), and six equivalent Co(2) atoms to form distorted AlCe3Co9 cuboctahedra that share corners with nine equivalent Co(1)Ce3Al3Co6 cuboctahedra, corners with twelve equivalent Co(2)Ce4Al2Co6 cuboctahedra, edges with six equivalent Al(1)Ce3Co9 cuboctahedra, faces with two equivalent Al(1)Ce3Co9 cuboctahedra, faces with three equivalent Co(1)Ce3Al3Co6 cuboctahedra, and faces with eighteen equivalent Co(2)Ce4Al2Co6 cuboctahedra.