Tm3Sc is beta Cu3Ti-like structured and crystallizes in the hexagonal P6_3/mmc space group. Tm(1) is bonded to eight equivalent Tm(1) and four equivalent Sc(1) atoms to form TmTm8Sc4 cuboctahedra that share corners with four equivalent Sc(1)Tm12 cuboctahedra, corners with fourteen equivalent Tm(1)Tm8Sc4 cuboctahedra, edges with six equivalent Sc(1)Tm12 cuboctahedra, edges with twelve equivalent Tm(1)Tm8Sc4 cuboctahedra, faces with four equivalent Sc(1)Tm12 cuboctahedra, and faces with sixteen equivalent Tm(1)Tm8Sc4 cuboctahedra. Sc(1) is bonded to twelve equivalent Tm(1) atoms to form ScTm12 cuboctahedra that share corners with six equivalent Sc(1)Tm12 cuboctahedra, corners with twelve equivalent Tm(1)Tm8Sc4 cuboctahedra, edges with eighteen equivalent Tm(1)Tm8Sc4 cuboctahedra, faces with eight equivalent Sc(1)Tm12 cuboctahedra, and faces with twelve equivalent Tm(1)Tm8Sc4 cuboctahedra.
Tm3Sc is beta Cu3Ti-like structured and crystallizes in the hexagonal P6_3/mmc space group. Tm(1) is bonded to eight equivalent Tm(1) and four equivalent Sc(1) atoms to form TmTm8Sc4 cuboctahedra that share corners with four equivalent Sc(1)Tm12 cuboctahedra, corners with fourteen equivalent Tm(1)Tm8Sc4 cuboctahedra, edges with six equivalent Sc(1)Tm12 cuboctahedra, edges with twelve equivalent Tm(1)Tm8Sc4 cuboctahedra, faces with four equivalent Sc(1)Tm12 cuboctahedra, and faces with sixteen equivalent Tm(1)Tm8Sc4 cuboctahedra. There are a spread of Tm(1)-Tm(1) bond distances ranging from 3.40-3.54 Å. There are two shorter (3.37 Å) and two longer (3.50 Å) Tm(1)-Sc(1) bond lengths. Sc(1) is bonded to twelve equivalent Tm(1) atoms to form ScTm12 cuboctahedra that share corners with six equivalent Sc(1)Tm12 cuboctahedra, corners with twelve equivalent Tm(1)Tm8Sc4 cuboctahedra, edges with eighteen equivalent Tm(1)Tm8Sc4 cuboctahedra, faces with eight equivalent Sc(1)Tm12 cuboctahedra, and faces with twelve equivalent Tm(1)Tm8Sc4 cuboctahedra.