Sm3Y is beta Cu3Ti-like structured and crystallizes in the hexagonal P6_3/mmc space group. Sm(1) is bonded to eight equivalent Sm(1) and four equivalent Y(1) atoms to form SmSm8Y4 cuboctahedra that share corners with four equivalent Y(1)Sm12 cuboctahedra, corners with fourteen equivalent Sm(1)Sm8Y4 cuboctahedra, edges with six equivalent Y(1)Sm12 cuboctahedra, edges with twelve equivalent Sm(1)Sm8Y4 cuboctahedra, faces with four equivalent Y(1)Sm12 cuboctahedra, and faces with sixteen equivalent Sm(1)Sm8Y4 cuboctahedra. Y(1) is bonded to twelve equivalent Sm(1) atoms to form YSm12 cuboctahedra that share corners with six equivalent Y(1)Sm12 cuboctahedra, corners with twelve equivalent Sm(1)Sm8Y4 cuboctahedra, edges with eighteen equivalent Sm(1)Sm8Y4 cuboctahedra, faces with eight equivalent Y(1)Sm12 cuboctahedra, and faces with twelve equivalent Sm(1)Sm8Y4 cuboctahedra.
Sm3Y is beta Cu3Ti-like structured and crystallizes in the hexagonal P6_3/mmc space group. Sm(1) is bonded to eight equivalent Sm(1) and four equivalent Y(1) atoms to form SmSm8Y4 cuboctahedra that share corners with four equivalent Y(1)Sm12 cuboctahedra, corners with fourteen equivalent Sm(1)Sm8Y4 cuboctahedra, edges with six equivalent Y(1)Sm12 cuboctahedra, edges with twelve equivalent Sm(1)Sm8Y4 cuboctahedra, faces with four equivalent Y(1)Sm12 cuboctahedra, and faces with sixteen equivalent Sm(1)Sm8Y4 cuboctahedra. There are six shorter (3.65 Å) and two longer (3.73 Å) Sm(1)-Sm(1) bond lengths. There are two shorter (3.62 Å) and two longer (3.69 Å) Sm(1)-Y(1) bond lengths. Y(1) is bonded to twelve equivalent Sm(1) atoms to form YSm12 cuboctahedra that share corners with six equivalent Y(1)Sm12 cuboctahedra, corners with twelve equivalent Sm(1)Sm8Y4 cuboctahedra, edges with eighteen equivalent Sm(1)Sm8Y4 cuboctahedra, faces with eight equivalent Y(1)Sm12 cuboctahedra, and faces with twelve equivalent Sm(1)Sm8Y4 cuboctahedra.