Al3GeTi crystallizes in the tetragonal P4mm space group. Ti(1) is bonded to four equivalent Ti(1), two equivalent Al(2), two equivalent Al(3), two equivalent Al(4), and two equivalent Ge(1) atoms to form distorted TiTi4Al6Ge2 cuboctahedra that share corners with four equivalent Ti(1)Ti4Al6Ge2 cuboctahedra, corners with four equivalent Al(5)Al10Ge2 cuboctahedra, corners with two equivalent Al(1)Al4Ge5 square pyramids, edges with four equivalent Al(5)Al10Ge2 cuboctahedra, edges with four equivalent Al(3)Ti4Al8 cuboctahedra, edges with four equivalent Al(4)Ti4Al8 cuboctahedra,  a faceface with one Al(5)Al10Ge2 cuboctahedra, faces with two equivalent Al(3)Ti4Al8 cuboctahedra, faces with two equivalent Al(4)Ti4Al8 cuboctahedra, and faces with eight equivalent Ti(1)Ti4Al6Ge2 cuboctahedra. There are five inequivalent Al sites. In the first Al site, Al(1) is bonded to four equivalent Al(5), one Ge(1), and four equivalent Ge(2) atoms to form distorted AlAl4Ge5 square pyramids that share corners with four equivalent Ti(1)Ti4Al6Ge2 cuboctahedra, corners with four equivalent Al(3)Ti4Al8 cuboctahedra, corners with four equivalent Al(1)Al4Ge5 square pyramids, edges with four equivalent Al(4)Ti4Al8 cuboctahedra, edges with eight equivalent Al(5)Al10Ge2 cuboctahedra,  a faceface with one Al(3)Ti4Al8 cuboctahedra, faces with four equivalent Al(5)Al10Ge2 cuboctahedra, and faces with four equivalent Al(1)Al4Ge5 square pyramids. In the second Al site, Al(2) is bonded in a 9-coordinate geometry to four equivalent Ti(1), one Ge(2), and four equivalent Ge(1) atoms. In the third Al site, Al(3) is bonded to four equivalent Ti(1), four equivalent Al(4), and four equivalent Al(5) atoms to form AlTi4Al8 cuboctahedra that share corners with four equivalent Al(3)Ti4Al8 cuboctahedra, corners with four equivalent Al(1)Al4Ge5 square pyramids, edges with eight equivalent Ti(1)Ti4Al6Ge2 cuboctahedra, edges with eight equivalent Al(5)Al10Ge2 cuboctahedra, faces with four equivalent Ti(1)Ti4Al6Ge2 cuboctahedra, faces with four equivalent Al(5)Al10Ge2 cuboctahedra, faces with four equivalent Al(3)Ti4Al8 cuboctahedra, faces with four equivalent Al(4)Ti4Al8 cuboctahedra, and  a faceface with one Al(1)Al4Ge5 square pyramid. In the fourth Al site, Al(4) is bonded to four equivalent Ti(1), four equivalent Al(3), and four equivalent Al(5) atoms to form AlTi4Al8 cuboctahedra that share corners with four equivalent Al(4)Ti4Al8 cuboctahedra, edges with eight equivalent Ti(1)Ti4Al6Ge2 cuboctahedra, edges with eight equivalent Al(5)Al10Ge2 cuboctahedra, edges with four equivalent Al(1)Al4Ge5 square pyramids, faces with four equivalent Ti(1)Ti4Al6Ge2 cuboctahedra, faces with four equivalent Al(5)Al10Ge2 cuboctahedra, faces with four equivalent Al(3)Ti4Al8 cuboctahedra, and faces with four equivalent Al(4)Ti4Al8 cuboctahedra. In the fifth Al site, Al(5) is bonded to two equivalent Al(1), two equivalent Al(3), two equivalent Al(4), four equivalent Al(5), and two equivalent Ge(2) atoms to form distorted AlAl10Ge2 cuboctahedra that share corners with four equivalent Ti(1)Ti4Al6Ge2 cuboctahedra, corners with four equivalent Al(5)Al10Ge2 cuboctahedra, edges with four equivalent Ti(1)Ti4Al6Ge2 cuboctahedra, edges with four equivalent Al(3)Ti4Al8 cuboctahedra, edges with four equivalent Al(4)Ti4Al8 cuboctahedra, edges with four equivalent Al(1)Al4Ge5 square pyramids,  a faceface with one Ti(1)Ti4Al6Ge2 cuboctahedra, faces with two equivalent Al(3)Ti4Al8 cuboctahedra, faces with two equivalent Al(4)Ti4Al8 cuboctahedra, faces with eight equivalent Al(5)Al10Ge2 cuboctahedra, and faces with two equivalent Al(1)Al4Ge5 square pyramids. There are two inequivalent Ge sites. In the first Ge site, Ge(1) is bonded in a 9-coordinate geometry to four equivalent Ti(1), one Al(1), and four equivalent Al(2) atoms. In the second Ge site, Ge(2) is bonded in a 9-coordinate geometry to one Al(2), four equivalent Al(1), and four equivalent Al(5) atoms.
Al3GeTi crystallizes in the tetragonal P4mm space group. Ti(1) is bonded to four equivalent Ti(1), two equivalent Al(2), two equivalent Al(3), two equivalent Al(4), and two equivalent Ge(1) atoms to form distorted TiTi4Al6Ge2 cuboctahedra that share corners with four equivalent Ti(1)Ti4Al6Ge2 cuboctahedra, corners with four equivalent Al(5)Al10Ge2 cuboctahedra, corners with two equivalent Al(1)Al4Ge5 square pyramids, edges with four equivalent Al(5)Al10Ge2 cuboctahedra, edges with four equivalent Al(3)Ti4Al8 cuboctahedra, edges with four equivalent Al(4)Ti4Al8 cuboctahedra,  a faceface with one Al(5)Al10Ge2 cuboctahedra, faces with two equivalent Al(3)Ti4Al8 cuboctahedra, faces with two equivalent Al(4)Ti4Al8 cuboctahedra, and faces with eight equivalent Ti(1)Ti4Al6Ge2 cuboctahedra. All Ti(1)-Ti(1) bond lengths are 2.83 Å. Both Ti(1)-Al(2) bond lengths are 2.83 Å. Both Ti(1)-Al(3) bond lengths are 2.85 Å. Both Ti(1)-Al(4) bond lengths are 2.85 Å. Both Ti(1)-Ge(1) bond lengths are 2.73 Å. There are five inequivalent Al sites. In the first Al site, Al(1) is bonded to four equivalent Al(5), one Ge(1), and four equivalent Ge(2) atoms to form distorted AlAl4Ge5 square pyramids that share corners with four equivalent Ti(1)Ti4Al6Ge2 cuboctahedra, corners with four equivalent Al(3)Ti4Al8 cuboctahedra, corners with four equivalent Al(1)Al4Ge5 square pyramids, edges with four equivalent Al(4)Ti4Al8 cuboctahedra, edges with eight equivalent Al(5)Al10Ge2 cuboctahedra,  a faceface with one Al(3)Ti4Al8 cuboctahedra, faces with four equivalent Al(5)Al10Ge2 cuboctahedra, and faces with four equivalent Al(1)Al4Ge5 square pyramids. All Al(1)-Al(5) bond lengths are 2.91 Å. The Al(1)-Ge(1) bond length is 2.54 Å. All Al(1)-Ge(2) bond lengths are 2.84 Å. In the second Al site, Al(2) is bonded in a 9-coordinate geometry to four equivalent Ti(1), one Ge(2), and four equivalent Ge(1) atoms. The Al(2)-Ge(2) bond length is 2.57 Å. All Al(2)-Ge(1) bond lengths are 2.84 Å. In the third Al site, Al(3) is bonded to four equivalent Ti(1), four equivalent Al(4), and four equivalent Al(5) atoms to form AlTi4Al8 cuboctahedra that share corners with four equivalent Al(3)Ti4Al8 cuboctahedra, corners with four equivalent Al(1)Al4Ge5 square pyramids, edges with eight equivalent Ti(1)Ti4Al6Ge2 cuboctahedra, edges with eight equivalent Al(5)Al10Ge2 cuboctahedra, faces with four equivalent Ti(1)Ti4Al6Ge2 cuboctahedra, faces with four equivalent Al(5)Al10Ge2 cuboctahedra, faces with four equivalent Al(3)Ti4Al8 cuboctahedra, faces with four equivalent Al(4)Ti4Al8 cuboctahedra, and  a faceface with one Al(1)Al4Ge5 square pyramid. All Al(3)-Al(4) bond lengths are 2.83 Å. All Al(3)-Al(5) bond lengths are 2.88 Å. In the fourth Al site, Al(4) is bonded to four equivalent Ti(1), four equivalent Al(3), and four equivalent Al(5) atoms to form AlTi4Al8 cuboctahedra that share corners with four equivalent Al(4)Ti4Al8 cuboctahedra, edges with eight equivalent Ti(1)Ti4Al6Ge2 cuboctahedra, edges with eight equivalent Al(5)Al10Ge2 cuboctahedra, edges with four equivalent Al(1)Al4Ge5 square pyramids, faces with four equivalent Ti(1)Ti4Al6Ge2 cuboctahedra, faces with four equivalent Al(5)Al10Ge2 cuboctahedra, faces with four equivalent Al(3)Ti4Al8 cuboctahedra, and faces with four equivalent Al(4)Ti4Al8 cuboctahedra. All Al(4)-Al(5) bond lengths are 2.88 Å. In the fifth Al site, Al(5) is bonded to two equivalent Al(1), two equivalent Al(3), two equivalent Al(4), four equivalent Al(5), and two equivalent Ge(2) atoms to form distorted AlAl10Ge2 cuboctahedra that share corners with four equivalent Ti(1)Ti4Al6Ge2 cuboctahedra, corners with four equivalent Al(5)Al10Ge2 cuboctahedra, edges with four equivalent Ti(1)Ti4Al6Ge2 cuboctahedra, edges with four equivalent Al(3)Ti4Al8 cuboctahedra, edges with four equivalent Al(4)Ti4Al8 cuboctahedra, edges with four equivalent Al(1)Al4Ge5 square pyramids,  a faceface with one Ti(1)Ti4Al6Ge2 cuboctahedra, faces with two equivalent Al(3)Ti4Al8 cuboctahedra, faces with two equivalent Al(4)Ti4Al8 cuboctahedra, faces with eight equivalent Al(5)Al10Ge2 cuboctahedra, and faces with two equivalent Al(1)Al4Ge5 square pyramids. All Al(5)-Al(5) bond lengths are 2.83 Å. Both Al(5)-Ge(2) bond lengths are 2.78 Å. There are two inequivalent Ge sites. In the first Ge site, Ge(1) is bonded in a 9-coordinate geometry to four equivalent Ti(1), one Al(1), and four equivalent Al(2) atoms. In the second Ge site, Ge(2) is bonded in a 9-coordinate geometry to one Al(2), four equivalent Al(1), and four equivalent Al(5) atoms.