TiAl2 is beta Cu3Ti-like structured and crystallizes in the tetragonal I4_1/amd space group. Ti(1) is bonded to two equivalent Ti(1), four equivalent Al(2), and six equivalent Al(1) atoms to form distorted TiTi2Al10 cuboctahedra that share corners with four equivalent Al(2)Ti4Al8 cuboctahedra, corners with eight equivalent Ti(1)Ti2Al10 cuboctahedra, edges with four equivalent Ti(1)Ti2Al10 cuboctahedra, edges with eight equivalent Al(1)Ti6Al6 cuboctahedra, edges with twelve equivalent Al(2)Ti4Al8 cuboctahedra, faces with five equivalent Al(2)Ti4Al8 cuboctahedra, faces with six equivalent Al(1)Ti6Al6 cuboctahedra, and faces with seven equivalent Ti(1)Ti2Al10 cuboctahedra. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to six equivalent Ti(1), two equivalent Al(1), and four equivalent Al(2) atoms to form AlTi6Al6 cuboctahedra that share corners with four equivalent Al(2)Ti4Al8 cuboctahedra, corners with eight equivalent Al(1)Ti6Al6 cuboctahedra, edges with four equivalent Al(1)Ti6Al6 cuboctahedra, edges with eight equivalent Ti(1)Ti2Al10 cuboctahedra, edges with twelve equivalent Al(2)Ti4Al8 cuboctahedra, faces with five equivalent Al(2)Ti4Al8 cuboctahedra, faces with six equivalent Ti(1)Ti2Al10 cuboctahedra, and faces with seven equivalent Al(1)Ti6Al6 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 four equivalent Ti(1)Ti2Al10 cuboctahedra, corners with four equivalent Al(2)Ti4Al8 cuboctahedra, corners with four equivalent Al(1)Ti6Al6 cuboctahedra, edges with twelve equivalent Ti(1)Ti2Al10 cuboctahedra, edges with twelve equivalent Al(1)Ti6Al6 cuboctahedra, faces with five equivalent Ti(1)Ti2Al10 cuboctahedra, faces with five equivalent Al(1)Ti6Al6 cuboctahedra, and faces with eight equivalent Al(2)Ti4Al8 cuboctahedra.
TiAl2 is beta Cu3Ti-like structured and crystallizes in the tetragonal I4_1/amd space group. Ti(1) is bonded to two equivalent Ti(1), four equivalent Al(2), and six equivalent Al(1) atoms to form distorted TiTi2Al10 cuboctahedra that share corners with four equivalent Al(2)Ti4Al8 cuboctahedra, corners with eight equivalent Ti(1)Ti2Al10 cuboctahedra, edges with four equivalent Ti(1)Ti2Al10 cuboctahedra, edges with eight equivalent Al(1)Ti6Al6 cuboctahedra, edges with twelve equivalent Al(2)Ti4Al8 cuboctahedra, faces with five equivalent Al(2)Ti4Al8 cuboctahedra, faces with six equivalent Al(1)Ti6Al6 cuboctahedra, and faces with seven equivalent Ti(1)Ti2Al10 cuboctahedra. Both Ti(1)-Ti(1) bond lengths are 3.01 Å. All Ti(1)-Al(2) bond lengths are 2.73 Å. There are four shorter (2.80 Å) and two longer (2.86 Å) Ti(1)-Al(1) bond lengths. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to six equivalent Ti(1), two equivalent Al(1), and four equivalent Al(2) atoms to form AlTi6Al6 cuboctahedra that share corners with four equivalent Al(2)Ti4Al8 cuboctahedra, corners with eight equivalent Al(1)Ti6Al6 cuboctahedra, edges with four equivalent Al(1)Ti6Al6 cuboctahedra, edges with eight equivalent Ti(1)Ti2Al10 cuboctahedra, edges with twelve equivalent Al(2)Ti4Al8 cuboctahedra, faces with five equivalent Al(2)Ti4Al8 cuboctahedra, faces with six equivalent Ti(1)Ti2Al10 cuboctahedra, and faces with seven equivalent Al(1)Ti6Al6 cuboctahedra. Both Al(1)-Al(1) bond lengths are 2.72 Å. 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 four equivalent Ti(1)Ti2Al10 cuboctahedra, corners with four equivalent Al(2)Ti4Al8 cuboctahedra, corners with four equivalent Al(1)Ti6Al6 cuboctahedra, edges with twelve equivalent Ti(1)Ti2Al10 cuboctahedra, edges with twelve equivalent Al(1)Ti6Al6 cuboctahedra, faces with five equivalent Ti(1)Ti2Al10 cuboctahedra, faces with five equivalent Al(1)Ti6Al6 cuboctahedra, and faces with eight equivalent Al(2)Ti4Al8 cuboctahedra. All Al(2)-Al(2) bond lengths are 2.79 Å.