Mg13Al16 crystallizes in the cubic I-43m space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 12-coordinate geometry to six equivalent Mg(1), one Al(2), and five equivalent Al(1) atoms. In the second Mg site, Mg(2) is bonded in a 16-coordinate geometry to four equivalent Al(2) and twelve equivalent Al(1) atoms. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded in a 11-coordinate geometry to one Mg(2), five equivalent Mg(1), two equivalent Al(2), and three equivalent Al(1) atoms. In the second Al site, Al(2) is bonded in a 4-coordinate geometry to one Mg(2), three equivalent Mg(1), and six equivalent Al(1) atoms.
Mg13Al16 crystallizes in the cubic I-43m space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 12-coordinate geometry to six equivalent Mg(1), one Al(2), and five equivalent Al(1) atoms. There are two shorter (3.11 Å) and four longer (3.14 Å) Mg(1)-Mg(1) bond lengths. The Mg(1)-Al(2) bond length is 2.99 Å. There are a spread of Mg(1)-Al(1) bond distances ranging from 2.90-3.11 Å. In the second Mg site, Mg(2) is bonded in a 16-coordinate geometry to four equivalent Al(2) and twelve equivalent Al(1) atoms. All Mg(2)-Al(2) bond lengths are 3.10 Å. All Mg(2)-Al(1) bond lengths are 3.17 Å. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded in a 11-coordinate geometry to one Mg(2), five equivalent Mg(1), two equivalent Al(2), and three equivalent Al(1) atoms. Both Al(1)-Al(2) bond lengths are 3.06 Å. There is one shorter (2.66 Å) and two longer (2.74 Å) Al(1)-Al(1) bond lengths. In the second Al site, Al(2) is bonded in a 4-coordinate geometry to one Mg(2), three equivalent Mg(1), and six equivalent Al(1) atoms.