CeAl3 crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. Ce is bonded to twelve equivalent Al atoms to form a mixture of distorted corner and face-sharing CeAl12 cuboctahedra. There are six shorter (3.12 Å) and six longer (3.22 Å) Ce–Al bond lengths. Al is bonded in a 10-coordinate geometry to four equivalent Ce and six equivalent Al atoms. There are two shorter (2.79 Å) and four longer (2.82 Å) Al–Al bond lengths.