Pm3Ce is Magnesium-derived structured and crystallizes in the hexagonal P6_3/mmc space group. Pm(1) is bonded to eight equivalent Pm(1) and four equivalent Ce(1) atoms to form PmCe4Pm8 cuboctahedra that share corners with four equivalent Ce(1)Pm12 cuboctahedra, corners with fourteen equivalent Pm(1)Ce4Pm8 cuboctahedra, edges with six equivalent Ce(1)Pm12 cuboctahedra, edges with twelve equivalent Pm(1)Ce4Pm8 cuboctahedra, faces with four equivalent Ce(1)Pm12 cuboctahedra, and faces with sixteen equivalent Pm(1)Ce4Pm8 cuboctahedra. Ce(1) is bonded to twelve equivalent Pm(1) atoms to form CePm12 cuboctahedra that share corners with six equivalent Ce(1)Pm12 cuboctahedra, corners with twelve equivalent Pm(1)Ce4Pm8 cuboctahedra, edges with eighteen equivalent Pm(1)Ce4Pm8 cuboctahedra, faces with eight equivalent Ce(1)Pm12 cuboctahedra, and faces with twelve equivalent Pm(1)Ce4Pm8 cuboctahedra.
Pm3Ce is Magnesium-derived structured and crystallizes in the hexagonal P6_3/mmc space group. Pm(1) is bonded to eight equivalent Pm(1) and four equivalent Ce(1) atoms to form PmCe4Pm8 cuboctahedra that share corners with four equivalent Ce(1)Pm12 cuboctahedra, corners with fourteen equivalent Pm(1)Ce4Pm8 cuboctahedra, edges with six equivalent Ce(1)Pm12 cuboctahedra, edges with twelve equivalent Pm(1)Ce4Pm8 cuboctahedra, faces with four equivalent Ce(1)Pm12 cuboctahedra, and faces with sixteen equivalent Pm(1)Ce4Pm8 cuboctahedra. There are two shorter (3.66 Å) and six longer (3.67 Å) Pm(1)-Pm(1) bond lengths. There are two shorter (3.66 Å) and two longer (3.67 Å) Pm(1)-Ce(1) bond lengths. Ce(1) is bonded to twelve equivalent Pm(1) atoms to form CePm12 cuboctahedra that share corners with six equivalent Ce(1)Pm12 cuboctahedra, corners with twelve equivalent Pm(1)Ce4Pm8 cuboctahedra, edges with eighteen equivalent Pm(1)Ce4Pm8 cuboctahedra, faces with eight equivalent Ce(1)Pm12 cuboctahedra, and faces with twelve equivalent Pm(1)Ce4Pm8 cuboctahedra.