ThSm3 is beta Cu3Ti-like structured and crystallizes in the tetragonal I4/mmm space group. Th(1) is bonded to four equivalent Sm(2) and eight equivalent Sm(1) atoms to form ThSm12 cuboctahedra that share corners with four equivalent Th(1)Sm12 cuboctahedra, corners with eight equivalent Sm(2)Sm8Th4 cuboctahedra, edges with eight equivalent Th(1)Sm12 cuboctahedra, edges with sixteen equivalent Sm(1)Sm8Th4 cuboctahedra, faces with four equivalent Th(1)Sm12 cuboctahedra, faces with six equivalent Sm(2)Sm8Th4 cuboctahedra, and faces with eight equivalent Sm(1)Sm8Th4 cuboctahedra. There are two inequivalent Sm sites. In the first Sm site, Sm(1) is bonded to four equivalent Th(1), four equivalent Sm(1), and four equivalent Sm(2) atoms to form SmSm8Th4 cuboctahedra that share corners with twelve equivalent Sm(1)Sm8Th4 cuboctahedra, edges with eight equivalent Th(1)Sm12 cuboctahedra, edges with eight equivalent Sm(1)Sm8Th4 cuboctahedra, edges with eight equivalent Sm(2)Sm8Th4 cuboctahedra, faces with four equivalent Th(1)Sm12 cuboctahedra, faces with four equivalent Sm(2)Sm8Th4 cuboctahedra, and faces with ten equivalent Sm(1)Sm8Th4 cuboctahedra. In the second Sm site, Sm(2) is bonded to four equivalent Th(1) and eight equivalent Sm(1) atoms to form SmSm8Th4 cuboctahedra that share corners with four equivalent Sm(2)Sm8Th4 cuboctahedra, corners with eight equivalent Th(1)Sm12 cuboctahedra, edges with eight equivalent Sm(2)Sm8Th4 cuboctahedra, edges with sixteen equivalent Sm(1)Sm8Th4 cuboctahedra, faces with four equivalent Sm(2)Sm8Th4 cuboctahedra, faces with six equivalent Th(1)Sm12 cuboctahedra, and faces with eight equivalent Sm(1)Sm8Th4 cuboctahedra.
ThSm3 is beta Cu3Ti-like structured and crystallizes in the tetragonal I4/mmm space group. Th(1) is bonded to four equivalent Sm(2) and eight equivalent Sm(1) atoms to form ThSm12 cuboctahedra that share corners with four equivalent Th(1)Sm12 cuboctahedra, corners with eight equivalent Sm(2)Sm8Th4 cuboctahedra, edges with eight equivalent Th(1)Sm12 cuboctahedra, edges with sixteen equivalent Sm(1)Sm8Th4 cuboctahedra, faces with four equivalent Th(1)Sm12 cuboctahedra, faces with six equivalent Sm(2)Sm8Th4 cuboctahedra, and faces with eight equivalent Sm(1)Sm8Th4 cuboctahedra. All Th(1)-Sm(2) bond lengths are 3.61 Å. All Th(1)-Sm(1) bond lengths are 3.61 Å. There are two inequivalent Sm sites. In the first Sm site, Sm(1) is bonded to four equivalent Th(1), four equivalent Sm(1), and four equivalent Sm(2) atoms to form SmSm8Th4 cuboctahedra that share corners with twelve equivalent Sm(1)Sm8Th4 cuboctahedra, edges with eight equivalent Th(1)Sm12 cuboctahedra, edges with eight equivalent Sm(1)Sm8Th4 cuboctahedra, edges with eight equivalent Sm(2)Sm8Th4 cuboctahedra, faces with four equivalent Th(1)Sm12 cuboctahedra, faces with four equivalent Sm(2)Sm8Th4 cuboctahedra, and faces with ten equivalent Sm(1)Sm8Th4 cuboctahedra. All Sm(1)-Sm(1) bond lengths are 3.61 Å. All Sm(1)-Sm(2) bond lengths are 3.61 Å. In the second Sm site, Sm(2) is bonded to four equivalent Th(1) and eight equivalent Sm(1) atoms to form SmSm8Th4 cuboctahedra that share corners with four equivalent Sm(2)Sm8Th4 cuboctahedra, corners with eight equivalent Th(1)Sm12 cuboctahedra, edges with eight equivalent Sm(2)Sm8Th4 cuboctahedra, edges with sixteen equivalent Sm(1)Sm8Th4 cuboctahedra, faces with four equivalent Sm(2)Sm8Th4 cuboctahedra, faces with six equivalent Th(1)Sm12 cuboctahedra, and faces with eight equivalent Sm(1)Sm8Th4 cuboctahedra.