Ba7Al13 crystallizes in the trigonal P-3m1 space group. There are four inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 12-coordinate geometry to three equivalent Al(1), three equivalent Al(3), and six equivalent Al(2) atoms. In the second Ba site, Ba(2) is bonded in a 10-coordinate geometry to four equivalent Al(4) and six equivalent Al(2) atoms. In the third Ba site, Ba(3) is bonded in a 12-coordinate geometry to three equivalent Al(2), three equivalent Al(3), and six equivalent Al(1) atoms. In the fourth Ba site, Ba(4) is bonded in a 6-coordinate geometry to six equivalent Al(4) atoms. There are four inequivalent Al sites. In the first Al site, Al(1) is bonded in a 10-coordinate geometry to two equivalent Ba(1), four equivalent Ba(3), and four equivalent Al(1) atoms. In the second Al site, Al(2) is bonded in a 9-coordinate geometry to one Ba(3), two equivalent Ba(1), two equivalent Ba(2), one Al(3), one Al(4), and two equivalent Al(2) atoms. In the third Al site, Al(3) is bonded in a 9-coordinate geometry to three equivalent Ba(1), three equivalent Ba(3), and three equivalent Al(2) atoms. In the fourth Al site, Al(4) is bonded in a 10-coordinate geometry to three equivalent Ba(4), four equivalent Ba(2), and three equivalent Al(2) atoms.
Ba7Al13 crystallizes in the trigonal P-3m1 space group. There are four inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 12-coordinate geometry to three equivalent Al(1), three equivalent Al(3), and six equivalent Al(2) atoms. All Ba(1)-Al(1) bond lengths are 3.55 Å. All Ba(1)-Al(3) bond lengths are 3.53 Å. All Ba(1)-Al(2) bond lengths are 3.54 Å. In the second Ba site, Ba(2) is bonded in a 10-coordinate geometry to four equivalent Al(4) and six equivalent Al(2) atoms. There are three shorter (3.50 Å) and one longer (3.59 Å) Ba(2)-Al(4) bond length. All Ba(2)-Al(2) bond lengths are 3.57 Å. In the third Ba site, Ba(3) is bonded in a 12-coordinate geometry to three equivalent Al(2), three equivalent Al(3), and six equivalent Al(1) atoms. All Ba(3)-Al(2) bond lengths are 3.50 Å. All Ba(3)-Al(3) bond lengths are 3.59 Å. All Ba(3)-Al(1) bond lengths are 3.55 Å. In the fourth Ba site, Ba(4) is bonded in a 6-coordinate geometry to six equivalent Al(4) atoms. All Ba(4)-Al(4) bond lengths are 3.90 Å. There are four inequivalent Al sites. In the first Al site, Al(1) is bonded in a 10-coordinate geometry to two equivalent Ba(1), four equivalent Ba(3), and four equivalent Al(1) atoms. All Al(1)-Al(1) bond lengths are 3.03 Å. In the second Al site, Al(2) is bonded in a 9-coordinate geometry to one Ba(3), two equivalent Ba(1), two equivalent Ba(2), one Al(3), one Al(4), and two equivalent Al(2) atoms. The Al(2)-Al(3) bond length is 2.88 Å. The Al(2)-Al(4) bond length is 2.70 Å. Both Al(2)-Al(2) bond lengths are 2.94 Å. In the third Al site, Al(3) is bonded in a 9-coordinate geometry to three equivalent Ba(1), three equivalent Ba(3), and three equivalent Al(2) atoms. In the fourth Al site, Al(4) is bonded in a 10-coordinate geometry to three equivalent Ba(4), four equivalent Ba(2), and three equivalent Al(2) atoms.