BaAl4 crystallizes in the tetragonal I4/mmm space group. Ba(1) is bonded in a 16-coordinate geometry to eight equivalent Al(1) and eight equivalent Al(2) atoms. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded in a 8-coordinate geometry to four equivalent Ba(1) and four equivalent Al(2) atoms. In the second Al site, Al(2) is bonded in a 9-coordinate geometry to four equivalent Ba(1), one Al(2), and four equivalent Al(1) atoms.
BaAl4 crystallizes in the tetragonal I4/mmm space group. Ba(1) is bonded in a 16-coordinate geometry to eight equivalent Al(1) and eight equivalent Al(2) atoms. All Ba(1)-Al(1) bond lengths are 3.64 Å. All Ba(1)-Al(2) bond lengths are 3.50 Å. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded in a 8-coordinate geometry to four equivalent Ba(1) and four equivalent Al(2) atoms. All Al(1)-Al(2) bond lengths are 2.72 Å. In the second Al site, Al(2) is bonded in a 9-coordinate geometry to four equivalent Ba(1), one Al(2), and four equivalent Al(1) atoms. The Al(2)-Al(2) bond length is 2.72 Å.