Al3Ti is beta Cu3Ti-like structured and crystallizes in the tetragonal I4/mmm space group. Ti(1) is bonded to four equivalent Al(1) and eight equivalent Al(2) atoms to form TiAl12 cuboctahedra that share corners with four equivalent Ti(1)Al12 cuboctahedra, corners with eight equivalent Al(1)Ti4Al8 cuboctahedra, edges with eight equivalent Ti(1)Al12 cuboctahedra, edges with sixteen equivalent Al(2)Ti4Al8 cuboctahedra, faces with four equivalent Ti(1)Al12 cuboctahedra, faces with six equivalent Al(1)Ti4Al8 cuboctahedra, and faces with eight equivalent Al(2)Ti4Al8 cuboctahedra. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to four equivalent Ti(1) and eight equivalent Al(2) atoms to form AlTi4Al8 cuboctahedra that share corners with four equivalent Al(1)Ti4Al8 cuboctahedra, corners with eight equivalent Ti(1)Al12 cuboctahedra, edges with eight equivalent Al(1)Ti4Al8 cuboctahedra, edges with sixteen equivalent Al(2)Ti4Al8 cuboctahedra, faces with four equivalent Al(1)Ti4Al8 cuboctahedra, faces with six equivalent Ti(1)Al12 cuboctahedra, and faces with eight equivalent Al(2)Ti4Al8 cuboctahedra. In the second Al site, Al(2) is bonded to four equivalent Ti(1), four equivalent Al(1), and four equivalent Al(2) atoms to form AlTi4Al8 cuboctahedra that share corners with twelve equivalent Al(2)Ti4Al8 cuboctahedra, edges with eight equivalent Ti(1)Al12 cuboctahedra, edges with eight equivalent Al(1)Ti4Al8 cuboctahedra, edges with eight equivalent Al(2)Ti4Al8 cuboctahedra, faces with four equivalent Ti(1)Al12 cuboctahedra, faces with four equivalent Al(1)Ti4Al8 cuboctahedra, and faces with ten equivalent Al(2)Ti4Al8 cuboctahedra.
Al3Ti is beta Cu3Ti-like structured and crystallizes in the tetragonal I4/mmm space group. Ti(1) is bonded to four equivalent Al(1) and eight equivalent Al(2) atoms to form TiAl12 cuboctahedra that share corners with four equivalent Ti(1)Al12 cuboctahedra, corners with eight equivalent Al(1)Ti4Al8 cuboctahedra, edges with eight equivalent Ti(1)Al12 cuboctahedra, edges with sixteen equivalent Al(2)Ti4Al8 cuboctahedra, faces with four equivalent Ti(1)Al12 cuboctahedra, faces with six equivalent Al(1)Ti4Al8 cuboctahedra, and faces with eight equivalent Al(2)Ti4Al8 cuboctahedra. All Ti(1)-Al(1) bond lengths are 2.70 Å. All Ti(1)-Al(2) bond lengths are 2.87 Å. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to four equivalent Ti(1) and eight equivalent Al(2) atoms to form AlTi4Al8 cuboctahedra that share corners with four equivalent Al(1)Ti4Al8 cuboctahedra, corners with eight equivalent Ti(1)Al12 cuboctahedra, edges with eight equivalent Al(1)Ti4Al8 cuboctahedra, edges with sixteen equivalent Al(2)Ti4Al8 cuboctahedra, faces with four equivalent Al(1)Ti4Al8 cuboctahedra, faces with six equivalent Ti(1)Al12 cuboctahedra, and faces with eight equivalent Al(2)Ti4Al8 cuboctahedra. All Al(1)-Al(2) bond lengths are 2.87 Å. In the second Al site, Al(2) is bonded to four equivalent Ti(1), four equivalent Al(1), and four equivalent Al(2) atoms to form AlTi4Al8 cuboctahedra that share corners with twelve equivalent Al(2)Ti4Al8 cuboctahedra, edges with eight equivalent Ti(1)Al12 cuboctahedra, edges with eight equivalent Al(1)Ti4Al8 cuboctahedra, edges with eight equivalent Al(2)Ti4Al8 cuboctahedra, faces with four equivalent Ti(1)Al12 cuboctahedra, faces with four equivalent Al(1)Ti4Al8 cuboctahedra, and faces with ten equivalent Al(2)Ti4Al8 cuboctahedra. All Al(2)-Al(2) bond lengths are 2.70 Å.