AcCe3 is alpha La-derived structured and crystallizes in the tetragonal I4/mmm space group. Ac(1) is bonded to four equivalent Ce(2) and eight equivalent Ce(1) atoms to form AcCe12 cuboctahedra that share corners with four equivalent Ac(1)Ce12 cuboctahedra, corners with eight equivalent Ce(2)Ac4Ce8 cuboctahedra, edges with eight equivalent Ac(1)Ce12 cuboctahedra, edges with sixteen equivalent Ce(1)Ac4Ce8 cuboctahedra, faces with four equivalent Ac(1)Ce12 cuboctahedra, faces with six equivalent Ce(2)Ac4Ce8 cuboctahedra, and faces with eight equivalent Ce(1)Ac4Ce8 cuboctahedra. There are two inequivalent Ce sites. In the first Ce site, Ce(1) is bonded to four equivalent Ac(1), four equivalent Ce(1), and four equivalent Ce(2) atoms to form CeAc4Ce8 cuboctahedra that share corners with twelve equivalent Ce(1)Ac4Ce8 cuboctahedra, edges with eight equivalent Ac(1)Ce12 cuboctahedra, edges with eight equivalent Ce(1)Ac4Ce8 cuboctahedra, edges with eight equivalent Ce(2)Ac4Ce8 cuboctahedra, faces with four equivalent Ac(1)Ce12 cuboctahedra, faces with four equivalent Ce(2)Ac4Ce8 cuboctahedra, and faces with ten equivalent Ce(1)Ac4Ce8 cuboctahedra. In the second Ce site, Ce(2) is bonded to four equivalent Ac(1) and eight equivalent Ce(1) atoms to form CeAc4Ce8 cuboctahedra that share corners with four equivalent Ce(2)Ac4Ce8 cuboctahedra, corners with eight equivalent Ac(1)Ce12 cuboctahedra, edges with eight equivalent Ce(2)Ac4Ce8 cuboctahedra, edges with sixteen equivalent Ce(1)Ac4Ce8 cuboctahedra, faces with four equivalent Ce(2)Ac4Ce8 cuboctahedra, faces with six equivalent Ac(1)Ce12 cuboctahedra, and faces with eight equivalent Ce(1)Ac4Ce8 cuboctahedra.
AcCe3 is alpha La-derived structured and crystallizes in the tetragonal I4/mmm space group. Ac(1) is bonded to four equivalent Ce(2) and eight equivalent Ce(1) atoms to form AcCe12 cuboctahedra that share corners with four equivalent Ac(1)Ce12 cuboctahedra, corners with eight equivalent Ce(2)Ac4Ce8 cuboctahedra, edges with eight equivalent Ac(1)Ce12 cuboctahedra, edges with sixteen equivalent Ce(1)Ac4Ce8 cuboctahedra, faces with four equivalent Ac(1)Ce12 cuboctahedra, faces with six equivalent Ce(2)Ac4Ce8 cuboctahedra, and faces with eight equivalent Ce(1)Ac4Ce8 cuboctahedra. All Ac(1)-Ce(2) bond lengths are 3.53 Å. All Ac(1)-Ce(1) bond lengths are 3.54 Å. There are two inequivalent Ce sites. In the first Ce site, Ce(1) is bonded to four equivalent Ac(1), four equivalent Ce(1), and four equivalent Ce(2) atoms to form CeAc4Ce8 cuboctahedra that share corners with twelve equivalent Ce(1)Ac4Ce8 cuboctahedra, edges with eight equivalent Ac(1)Ce12 cuboctahedra, edges with eight equivalent Ce(1)Ac4Ce8 cuboctahedra, edges with eight equivalent Ce(2)Ac4Ce8 cuboctahedra, faces with four equivalent Ac(1)Ce12 cuboctahedra, faces with four equivalent Ce(2)Ac4Ce8 cuboctahedra, and faces with ten equivalent Ce(1)Ac4Ce8 cuboctahedra. All Ce(1)-Ce(1) bond lengths are 3.53 Å. All Ce(1)-Ce(2) bond lengths are 3.54 Å. In the second Ce site, Ce(2) is bonded to four equivalent Ac(1) and eight equivalent Ce(1) atoms to form CeAc4Ce8 cuboctahedra that share corners with four equivalent Ce(2)Ac4Ce8 cuboctahedra, corners with eight equivalent Ac(1)Ce12 cuboctahedra, edges with eight equivalent Ce(2)Ac4Ce8 cuboctahedra, edges with sixteen equivalent Ce(1)Ac4Ce8 cuboctahedra, faces with four equivalent Ce(2)Ac4Ce8 cuboctahedra, faces with six equivalent Ac(1)Ce12 cuboctahedra, and faces with eight equivalent Ce(1)Ac4Ce8 cuboctahedra.