Al3Ge is beta Cu3Ti-like structured and crystallizes in the tetragonal I4/mmm space group. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to four equivalent Al(1), four equivalent Al(2), and four equivalent Ge(1) atoms to form distorted AlAl8Ge4 cuboctahedra that share corners with twelve equivalent Al(1)Al8Ge4 cuboctahedra, edges with eight equivalent Al(1)Al8Ge4 cuboctahedra, edges with eight equivalent Al(2)Al8Ge4 cuboctahedra, edges with eight equivalent Ge(1)Al12 cuboctahedra, faces with four equivalent Al(2)Al8Ge4 cuboctahedra, faces with four equivalent Ge(1)Al12 cuboctahedra, and faces with ten equivalent Al(1)Al8Ge4 cuboctahedra. In the second Al site, Al(2) is bonded to eight equivalent Al(1) and four equivalent Ge(1) atoms to form AlAl8Ge4 cuboctahedra that share corners with four equivalent Al(2)Al8Ge4 cuboctahedra, corners with eight equivalent Ge(1)Al12 cuboctahedra, edges with eight equivalent Al(2)Al8Ge4 cuboctahedra, edges with sixteen equivalent Al(1)Al8Ge4 cuboctahedra, faces with four equivalent Al(2)Al8Ge4 cuboctahedra, faces with six equivalent Ge(1)Al12 cuboctahedra, and faces with eight equivalent Al(1)Al8Ge4 cuboctahedra. Ge(1) is bonded to four equivalent Al(2) and eight equivalent Al(1) atoms to form GeAl12 cuboctahedra that share corners with four equivalent Ge(1)Al12 cuboctahedra, corners with eight equivalent Al(2)Al8Ge4 cuboctahedra, edges with eight equivalent Ge(1)Al12 cuboctahedra, edges with sixteen equivalent Al(1)Al8Ge4 cuboctahedra, faces with four equivalent Ge(1)Al12 cuboctahedra, faces with six equivalent Al(2)Al8Ge4 cuboctahedra, and faces with eight equivalent Al(1)Al8Ge4 cuboctahedra.
Al3Ge is beta Cu3Ti-like structured and crystallizes in the tetragonal I4/mmm space group. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to four equivalent Al(1), four equivalent Al(2), and four equivalent Ge(1) atoms to form distorted AlAl8Ge4 cuboctahedra that share corners with twelve equivalent Al(1)Al8Ge4 cuboctahedra, edges with eight equivalent Al(1)Al8Ge4 cuboctahedra, edges with eight equivalent Al(2)Al8Ge4 cuboctahedra, edges with eight equivalent Ge(1)Al12 cuboctahedra, faces with four equivalent Al(2)Al8Ge4 cuboctahedra, faces with four equivalent Ge(1)Al12 cuboctahedra, and faces with ten equivalent Al(1)Al8Ge4 cuboctahedra. All Al(1)-Al(1) bond lengths are 2.90 Å. All Al(1)-Al(2) bond lengths are 2.89 Å. All Al(1)-Ge(1) bond lengths are 2.89 Å. In the second Al site, Al(2) is bonded to eight equivalent Al(1) and four equivalent Ge(1) atoms to form AlAl8Ge4 cuboctahedra that share corners with four equivalent Al(2)Al8Ge4 cuboctahedra, corners with eight equivalent Ge(1)Al12 cuboctahedra, edges with eight equivalent Al(2)Al8Ge4 cuboctahedra, edges with sixteen equivalent Al(1)Al8Ge4 cuboctahedra, faces with four equivalent Al(2)Al8Ge4 cuboctahedra, faces with six equivalent Ge(1)Al12 cuboctahedra, and faces with eight equivalent Al(1)Al8Ge4 cuboctahedra. All Al(2)-Ge(1) bond lengths are 2.90 Å. Ge(1) is bonded to four equivalent Al(2) and eight equivalent Al(1) atoms to form GeAl12 cuboctahedra that share corners with four equivalent Ge(1)Al12 cuboctahedra, corners with eight equivalent Al(2)Al8Ge4 cuboctahedra, edges with eight equivalent Ge(1)Al12 cuboctahedra, edges with sixteen equivalent Al(1)Al8Ge4 cuboctahedra, faces with four equivalent Ge(1)Al12 cuboctahedra, faces with six equivalent Al(2)Al8Ge4 cuboctahedra, and faces with eight equivalent Al(1)Al8Ge4 cuboctahedra.