Mg17Al12 crystallizes in the cubic I-43m space group. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 16-coordinate geometry to four equivalent Mg(2) and twelve equivalent Al(1) atoms. In the second Mg site, Mg(2) is bonded in a 10-coordinate geometry to one Mg(1), three equivalent Mg(3), and six equivalent Al(1) atoms. In the third Mg site, Mg(3) is bonded in a 12-coordinate geometry to one Mg(2), six equivalent Mg(3), and five equivalent Al(1) atoms. Al(1) is bonded in a 11-coordinate geometry to one Mg(1), two equivalent Mg(2), five equivalent Mg(3), and three equivalent Al(1) atoms.
Mg17Al12 crystallizes in the cubic I-43m space group. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 16-coordinate geometry to four equivalent Mg(2) and twelve equivalent Al(1) atoms. All Mg(1)-Mg(2) bond lengths are 3.13 Å. All Mg(1)-Al(1) bond lengths are 3.18 Å. In the second Mg site, Mg(2) is bonded in a 10-coordinate geometry to one Mg(1), three equivalent Mg(3), and six equivalent Al(1) atoms. All Mg(2)-Mg(3) bond lengths are 3.02 Å. All Mg(2)-Al(1) bond lengths are 3.08 Å. In the third Mg site, Mg(3) is bonded in a 12-coordinate geometry to one Mg(2), six equivalent Mg(3), and five equivalent Al(1) atoms. There are two shorter (3.11 Å) and four longer (3.13 Å) Mg(3)-Mg(3) bond lengths. There are a spread of Mg(3)-Al(1) bond distances ranging from 2.87-3.15 Å. Al(1) is bonded in a 11-coordinate geometry to one Mg(1), two equivalent Mg(2), five equivalent Mg(3), and three equivalent Al(1) atoms. There is one shorter (2.67 Å) and two longer (2.74 Å) Al(1)-Al(1) bond lengths.