DOE OSTI2020
CeAl4 crystallizes in the orthorhombic Imm2 space group. The structure is three-dimensional. there are two inequivalent Ce sites. In the first Ce site, Ce is bonded in a 8-coordinate geometry to sixteen Al atoms. There are a spread of Ce–Al bond distances ranging from 3.24–3.66 Å. In the second Ce site, Ce is bonded in a 8-coordinate geometry to sixteen Al atoms. There are a spread of Ce–Al bond distances ranging from 3.26–3.62 Å. There are eight inequivalent Al sites. In the first Al site, Al is bonded in a 9-coordinate geometry to four equivalent Ce and five Al atoms. There are a spread of Al–Al bond distances ranging from 2.51–2.67 Å. In the second Al site, Al is bonded in a 9-coordinate geometry to four equivalent Ce and five Al atoms. There are two shorter (2.64 Å) and two longer (2.66 Å) Al–Al bond lengths. In the third Al site, Al is bonded to four Ce and eight Al atoms to form a mixture of distorted corner, edge, and face-sharing AlCe4Al8 cuboctahedra. There are two shorter (2.66 Å) and four longer (3.05 Å) Al–Al bond lengths. In the fourth Al site, Al is bonded to four Ce and eight Al atoms to form a mixture of distorted corner, edge, and face-sharing AlCe4Al8 cuboctahedra. There are two shorter (2.67 Å) and four longer (2.98 Å) Al–Al bond lengths. In the fifth Al site, Al is bonded to four Ce and eight Al atoms to form a mixture of distorted corner, edge, and face-sharing AlCe4Al8 cuboctahedra. There are three shorter (2.66 Å) and two longer (3.01 Å) Al–Al bond lengths. In the sixth Al site, Al is bonded in a 9-coordinate geometry to four Ce and five Al atoms. There are one shorter (2.52 Å) and two longer (2.65 Å) Al–Al bond lengths. In the seventh Al site, Al is bonded in a 9-coordinate geometry to four Ce and five Al atoms. The Al–Al bond length is 2.66 Å. In the eighth Al site, Al is bonded to four Ce and eight Al atoms to form a mixture of distorted corner, edge, and face-sharing AlCe4Al8 cuboctahedra.