Er3Ce is beta Cu3Ti-like structured and crystallizes in the hexagonal P6_3/mmc space group. Er(1) is bonded to eight equivalent Er(1) and four equivalent Ce(1) atoms to form ErCe4Er8 cuboctahedra that share corners with four equivalent Ce(1)Er12 cuboctahedra, corners with fourteen equivalent Er(1)Ce4Er8 cuboctahedra, edges with six equivalent Ce(1)Er12 cuboctahedra, edges with twelve equivalent Er(1)Ce4Er8 cuboctahedra, faces with four equivalent Ce(1)Er12 cuboctahedra, and faces with sixteen equivalent Er(1)Ce4Er8 cuboctahedra. Ce(1) is bonded to twelve equivalent Er(1) atoms to form CeEr12 cuboctahedra that share corners with six equivalent Ce(1)Er12 cuboctahedra, corners with twelve equivalent Er(1)Ce4Er8 cuboctahedra, edges with eighteen equivalent Er(1)Ce4Er8 cuboctahedra, faces with eight equivalent Ce(1)Er12 cuboctahedra, and faces with twelve equivalent Er(1)Ce4Er8 cuboctahedra.
Er3Ce is beta Cu3Ti-like structured and crystallizes in the hexagonal P6_3/mmc space group. Er(1) is bonded to eight equivalent Er(1) and four equivalent Ce(1) atoms to form ErCe4Er8 cuboctahedra that share corners with four equivalent Ce(1)Er12 cuboctahedra, corners with fourteen equivalent Er(1)Ce4Er8 cuboctahedra, edges with six equivalent Ce(1)Er12 cuboctahedra, edges with twelve equivalent Er(1)Ce4Er8 cuboctahedra, faces with four equivalent Ce(1)Er12 cuboctahedra, and faces with sixteen equivalent Er(1)Ce4Er8 cuboctahedra. There are a spread of Er(1)-Er(1) bond distances ranging from 3.50-3.58 Å. There are two shorter (3.52 Å) and two longer (3.56 Å) Er(1)-Ce(1) bond lengths. Ce(1) is bonded to twelve equivalent Er(1) atoms to form CeEr12 cuboctahedra that share corners with six equivalent Ce(1)Er12 cuboctahedra, corners with twelve equivalent Er(1)Ce4Er8 cuboctahedra, edges with eighteen equivalent Er(1)Ce4Er8 cuboctahedra, faces with eight equivalent Ce(1)Er12 cuboctahedra, and faces with twelve equivalent Er(1)Ce4Er8 cuboctahedra.