Tm3Sn is Uranium Silicide-like structured and crystallizes in the tetragonal I4/mmm space group. There are two inequivalent Tm sites. In the first Tm site, Tm(1) is bonded to four equivalent Tm(1), four equivalent Tm(2), and four equivalent Sn(1) atoms to form distorted TmTm8Sn4 cuboctahedra that share corners with twelve equivalent Tm(1)Tm8Sn4 cuboctahedra, edges with eight equivalent Tm(1)Tm8Sn4 cuboctahedra, edges with eight equivalent Sn(1)Tm12 cuboctahedra, faces with four equivalent Sn(1)Tm12 cuboctahedra, and faces with ten equivalent Tm(1)Tm8Sn4 cuboctahedra. In the second Tm site, Tm(2) is bonded in a square co-planar geometry to eight equivalent Tm(1) and four equivalent Sn(1) atoms. Sn(1) is bonded to four equivalent Tm(2) and eight equivalent Tm(1) atoms to form SnTm12 cuboctahedra that share corners with four equivalent Sn(1)Tm12 cuboctahedra, edges with eight equivalent Sn(1)Tm12 cuboctahedra, edges with sixteen equivalent Tm(1)Tm8Sn4 cuboctahedra, faces with four equivalent Sn(1)Tm12 cuboctahedra, and faces with eight equivalent Tm(1)Tm8Sn4 cuboctahedra.
Tm3Sn is Uranium Silicide-like structured and crystallizes in the tetragonal I4/mmm space group. There are two inequivalent Tm sites. In the first Tm site, Tm(1) is bonded to four equivalent Tm(1), four equivalent Tm(2), and four equivalent Sn(1) atoms to form distorted TmTm8Sn4 cuboctahedra that share corners with twelve equivalent Tm(1)Tm8Sn4 cuboctahedra, edges with eight equivalent Tm(1)Tm8Sn4 cuboctahedra, edges with eight equivalent Sn(1)Tm12 cuboctahedra, faces with four equivalent Sn(1)Tm12 cuboctahedra, and faces with ten equivalent Tm(1)Tm8Sn4 cuboctahedra. All Tm(1)-Tm(1) bond lengths are 3.22 Å. All Tm(1)-Tm(2) bond lengths are 3.45 Å. All Tm(1)-Sn(1) bond lengths are 3.45 Å. In the second Tm site, Tm(2) is bonded in a square co-planar geometry to eight equivalent Tm(1) and four equivalent Sn(1) atoms. All Tm(2)-Sn(1) bond lengths are 3.22 Å. Sn(1) is bonded to four equivalent Tm(2) and eight equivalent Tm(1) atoms to form SnTm12 cuboctahedra that share corners with four equivalent Sn(1)Tm12 cuboctahedra, edges with eight equivalent Sn(1)Tm12 cuboctahedra, edges with sixteen equivalent Tm(1)Tm8Sn4 cuboctahedra, faces with four equivalent Sn(1)Tm12 cuboctahedra, and faces with eight equivalent Tm(1)Tm8Sn4 cuboctahedra.