Tb2HfAl9 is Uranium Silicide-derived structured and crystallizes in the tetragonal P4/mmm space group. Tb(1) is bonded to four equivalent Al(2), four equivalent Al(3), and four equivalent Al(4) atoms to form TbAl12 cuboctahedra that share corners with four equivalent Hf(1)Al12 cuboctahedra, corners with eight equivalent Tb(1)Al12 cuboctahedra, edges with four equivalent Al(1)Hf4Al8 cuboctahedra, edges with eight equivalent Al(3)Tb2Hf2Al8 cuboctahedra, edges with eight equivalent Al(4)Tb4Al8 cuboctahedra,  a faceface with one Hf(1)Al12 cuboctahedra, faces with four equivalent Al(3)Tb2Hf2Al8 cuboctahedra, faces with four equivalent Al(4)Tb4Al8 cuboctahedra, and faces with five equivalent Tb(1)Al12 cuboctahedra. Hf(1) is bonded to four equivalent Al(1) and eight equivalent Al(3) atoms to form HfAl12 cuboctahedra that share corners with four equivalent Hf(1)Al12 cuboctahedra, corners with eight equivalent Tb(1)Al12 cuboctahedra, edges with sixteen equivalent Al(3)Tb2Hf2Al8 cuboctahedra, faces with two equivalent Tb(1)Al12 cuboctahedra, faces with four equivalent Hf(1)Al12 cuboctahedra, faces with four equivalent Al(1)Hf4Al8 cuboctahedra, and faces with eight equivalent Al(3)Tb2Hf2Al8 cuboctahedra. There are four inequivalent Al sites. In the first Al site, Al(1) is bonded to four equivalent Hf(1) and eight equivalent Al(3) atoms to form AlHf4Al8 cuboctahedra that share corners with four equivalent Al(1)Hf4Al8 cuboctahedra, edges with eight equivalent Tb(1)Al12 cuboctahedra, edges with sixteen equivalent Al(3)Tb2Hf2Al8 cuboctahedra, faces with four equivalent Hf(1)Al12 cuboctahedra, faces with four equivalent Al(1)Hf4Al8 cuboctahedra, and faces with eight equivalent Al(3)Tb2Hf2Al8 cuboctahedra. In the second Al site, Al(2) is bonded in a distorted rectangular see-saw-like geometry to four equivalent Tb(1), four equivalent Al(3), and four equivalent Al(4) atoms. In the third Al site, Al(3) is bonded to two equivalent Tb(1), two equivalent Hf(1), two equivalent Al(1), two equivalent Al(2), and four equivalent Al(3) atoms to form distorted AlTb2Hf2Al8 cuboctahedra that share corners with four equivalent Al(4)Tb4Al8 cuboctahedra, corners with eight equivalent Al(3)Tb2Hf2Al8 cuboctahedra, edges with four equivalent Tb(1)Al12 cuboctahedra, edges with four equivalent Hf(1)Al12 cuboctahedra, edges with four equivalent Al(1)Hf4Al8 cuboctahedra, edges with four equivalent Al(3)Tb2Hf2Al8 cuboctahedra, edges with four equivalent Al(4)Tb4Al8 cuboctahedra,  a faceface with one Al(4)Tb4Al8 cuboctahedra, faces with two equivalent Tb(1)Al12 cuboctahedra, faces with two equivalent Hf(1)Al12 cuboctahedra, faces with two equivalent Al(1)Hf4Al8 cuboctahedra, and faces with nine equivalent Al(3)Tb2Hf2Al8 cuboctahedra. In the fourth Al site, Al(4) is bonded to four equivalent Tb(1), four equivalent Al(2), and four equivalent Al(4) atoms to form distorted AlTb4Al8 cuboctahedra that share corners with four equivalent Al(4)Tb4Al8 cuboctahedra, corners with eight equivalent Al(3)Tb2Hf2Al8 cuboctahedra, edges with eight equivalent Tb(1)Al12 cuboctahedra, edges with eight equivalent Al(3)Tb2Hf2Al8 cuboctahedra, faces with two equivalent Al(3)Tb2Hf2Al8 cuboctahedra, faces with four equivalent Tb(1)Al12 cuboctahedra, and faces with eight equivalent Al(4)Tb4Al8 cuboctahedra.
Tb2HfAl9 is Uranium Silicide-derived structured and crystallizes in the tetragonal P4/mmm space group. Tb(1) is bonded to four equivalent Al(2), four equivalent Al(3), and four equivalent Al(4) atoms to form TbAl12 cuboctahedra that share corners with four equivalent Hf(1)Al12 cuboctahedra, corners with eight equivalent Tb(1)Al12 cuboctahedra, edges with four equivalent Al(1)Hf4Al8 cuboctahedra, edges with eight equivalent Al(3)Tb2Hf2Al8 cuboctahedra, edges with eight equivalent Al(4)Tb4Al8 cuboctahedra,  a faceface with one Hf(1)Al12 cuboctahedra, faces with four equivalent Al(3)Tb2Hf2Al8 cuboctahedra, faces with four equivalent Al(4)Tb4Al8 cuboctahedra, and faces with five equivalent Tb(1)Al12 cuboctahedra. All Tb(1)-Al(2) bond lengths are 2.98 Å. All Tb(1)-Al(3) bond lengths are 3.01 Å. All Tb(1)-Al(4) bond lengths are 3.02 Å. Hf(1) is bonded to four equivalent Al(1) and eight equivalent Al(3) atoms to form HfAl12 cuboctahedra that share corners with four equivalent Hf(1)Al12 cuboctahedra, corners with eight equivalent Tb(1)Al12 cuboctahedra, edges with sixteen equivalent Al(3)Tb2Hf2Al8 cuboctahedra, faces with two equivalent Tb(1)Al12 cuboctahedra, faces with four equivalent Hf(1)Al12 cuboctahedra, faces with four equivalent Al(1)Hf4Al8 cuboctahedra, and faces with eight equivalent Al(3)Tb2Hf2Al8 cuboctahedra. All Hf(1)-Al(1) bond lengths are 2.98 Å. All Hf(1)-Al(3) bond lengths are 2.90 Å. There are four inequivalent Al sites. In the first Al site, Al(1) is bonded to four equivalent Hf(1) and eight equivalent Al(3) atoms to form AlHf4Al8 cuboctahedra that share corners with four equivalent Al(1)Hf4Al8 cuboctahedra, edges with eight equivalent Tb(1)Al12 cuboctahedra, edges with sixteen equivalent Al(3)Tb2Hf2Al8 cuboctahedra, faces with four equivalent Hf(1)Al12 cuboctahedra, faces with four equivalent Al(1)Hf4Al8 cuboctahedra, and faces with eight equivalent Al(3)Tb2Hf2Al8 cuboctahedra. All Al(1)-Al(3) bond lengths are 2.90 Å. In the second Al site, Al(2) is bonded in a distorted rectangular see-saw-like geometry to four equivalent Tb(1), four equivalent Al(3), and four equivalent Al(4) atoms. All Al(2)-Al(3) bond lengths are 3.05 Å. All Al(2)-Al(4) bond lengths are 2.99 Å. In the third Al site, Al(3) is bonded to two equivalent Tb(1), two equivalent Hf(1), two equivalent Al(1), two equivalent Al(2), and four equivalent Al(3) atoms to form distorted AlTb2Hf2Al8 cuboctahedra that share corners with four equivalent Al(4)Tb4Al8 cuboctahedra, corners with eight equivalent Al(3)Tb2Hf2Al8 cuboctahedra, edges with four equivalent Tb(1)Al12 cuboctahedra, edges with four equivalent Hf(1)Al12 cuboctahedra, edges with four equivalent Al(1)Hf4Al8 cuboctahedra, edges with four equivalent Al(3)Tb2Hf2Al8 cuboctahedra, edges with four equivalent Al(4)Tb4Al8 cuboctahedra,  a faceface with one Al(4)Tb4Al8 cuboctahedra, faces with two equivalent Tb(1)Al12 cuboctahedra, faces with two equivalent Hf(1)Al12 cuboctahedra, faces with two equivalent Al(1)Hf4Al8 cuboctahedra, and faces with nine equivalent Al(3)Tb2Hf2Al8 cuboctahedra. All Al(3)-Al(3) bond lengths are 2.98 Å. In the fourth Al site, Al(4) is bonded to four equivalent Tb(1), four equivalent Al(2), and four equivalent Al(4) atoms to form distorted AlTb4Al8 cuboctahedra that share corners with four equivalent Al(4)Tb4Al8 cuboctahedra, corners with eight equivalent Al(3)Tb2Hf2Al8 cuboctahedra, edges with eight equivalent Tb(1)Al12 cuboctahedra, edges with eight equivalent Al(3)Tb2Hf2Al8 cuboctahedra, faces with two equivalent Al(3)Tb2Hf2Al8 cuboctahedra, faces with four equivalent Tb(1)Al12 cuboctahedra, and faces with eight equivalent Al(4)Tb4Al8 cuboctahedra. All Al(4)-Al(4) bond lengths are 2.98 Å.