EuSm3 is Magnesium-derived structured and crystallizes in the hexagonal P6_3/mmc space group. Eu(1) is bonded to twelve Sm(1,1) atoms to form EuSm12 cuboctahedra that share corners with six equivalent Eu(1)Sm12 cuboctahedra; corners with twelve Sm(1,1)Sm8Eu4 cuboctahedra; edges with eighteen Sm(1,1)Sm8Eu4 cuboctahedra; faces with eight equivalent Eu(1)Sm12 cuboctahedra; and faces with twelve Sm(1,1)Sm8Eu4 cuboctahedra. There are two inequivalent Sm sites. In the first Sm site, Sm(1) is bonded to four equivalent Eu(1) and eight Sm(1,1) atoms to form SmSm8Eu4 cuboctahedra that share corners with four equivalent Eu(1)Sm12 cuboctahedra; corners with fourteen equivalent Sm(1)Sm8Eu4 cuboctahedra; edges with six equivalent Eu(1)Sm12 cuboctahedra; edges with twelve Sm(1,1)Sm8Eu4 cuboctahedra; faces with four equivalent Eu(1)Sm12 cuboctahedra; and faces with sixteen Sm(1,1)Sm8Eu4 cuboctahedra. In the second Sm site, Sm(1) is bonded to four equivalent Eu(1) and eight equivalent Sm(1) atoms to form SmSm8Eu4 cuboctahedra that share corners with four equivalent Eu(1)Sm12 cuboctahedra; corners with fourteen Sm(1,1)Sm8Eu4 cuboctahedra; edges with six equivalent Eu(1)Sm12 cuboctahedra; edges with twelve equivalent Sm(1)Sm8Eu4 cuboctahedra; faces with four equivalent Eu(1)Sm12 cuboctahedra; and faces with sixteen Sm(1,1)Sm8Eu4 cuboctahedra.
EuSm3 is Magnesium-derived structured and crystallizes in the hexagonal P6_3/mmc space group. Eu(1) is bonded to twelve Sm(1,1) atoms to form EuSm12 cuboctahedra that share corners with six equivalent Eu(1)Sm12 cuboctahedra; corners with twelve Sm(1,1)Sm8Eu4 cuboctahedra; edges with eighteen Sm(1,1)Sm8Eu4 cuboctahedra; faces with eight equivalent Eu(1)Sm12 cuboctahedra; and faces with twelve Sm(1,1)Sm8Eu4 cuboctahedra. There are six shorter (3.69 Å) and six longer (3.70 Å) Eu(1)-Sm(1,1) bond lengths. There are two inequivalent Sm sites. In the first Sm site, Sm(1) is bonded to four equivalent Eu(1) and eight Sm(1,1) atoms to form SmSm8Eu4 cuboctahedra that share corners with four equivalent Eu(1)Sm12 cuboctahedra; corners with fourteen equivalent Sm(1)Sm8Eu4 cuboctahedra; edges with six equivalent Eu(1)Sm12 cuboctahedra; edges with twelve Sm(1,1)Sm8Eu4 cuboctahedra; faces with four equivalent Eu(1)Sm12 cuboctahedra; and faces with sixteen Sm(1,1)Sm8Eu4 cuboctahedra. There are a spread of Sm(1)-Sm(1,1) bond distances ranging from 3.64-3.77 Å. In the second Sm site, Sm(1) is bonded to four equivalent Eu(1) and eight equivalent Sm(1) atoms to form SmSm8Eu4 cuboctahedra that share corners with four equivalent Eu(1)Sm12 cuboctahedra; corners with fourteen Sm(1,1)Sm8Eu4 cuboctahedra; edges with six equivalent Eu(1)Sm12 cuboctahedra; edges with twelve equivalent Sm(1)Sm8Eu4 cuboctahedra; faces with four equivalent Eu(1)Sm12 cuboctahedra; and faces with sixteen Sm(1,1)Sm8Eu4 cuboctahedra.