Mg16AuAl12 crystallizes in the triclinic P1 space group. There are sixteen inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 16-coordinate geometry to one Mg(13), one Mg(3), one Mg(4), one Mg(8), one Al(1), one Al(10), one Al(11), one Al(12), one Al(2), one Al(3), one Al(4), one Al(5), one Al(6), one Al(7), one Al(8), and one Al(9) atom. In the second Mg site, Mg(2) is bonded in a 12-coordinate geometry to one Mg(10), one Mg(11), one Mg(15), one Mg(16), one Mg(4), one Mg(5), one Mg(6), one Al(11), one Al(12), one Al(2), one Al(3), and one Al(4) atom. In the third Mg site, Mg(3) is bonded in a 1-coordinate geometry to one Mg(1), one Mg(12), one Mg(15), one Mg(6), one Mg(9), one Au(1), one Al(11), one Al(12), one Al(3), one Al(4), one Al(6), and one Al(9) atom. In the fourth Mg site, Mg(4) is bonded in a 11-coordinate geometry to one Mg(1), one Mg(14), one Mg(2), one Mg(7), one Au(1), one Al(10), one Al(12), one Al(3), one Al(5), one Al(7), and one Al(8) atom. In the fifth Mg site, Mg(5) is bonded in a 6-coordinate geometry to one Mg(2), one Mg(6), one Mg(8), one Mg(9), one Au(1), one Al(1), one Al(2), one Al(3), one Al(8), and one Al(9) atom. In the sixth Mg site, Mg(6) is bonded in a 12-coordinate geometry to one Mg(10), one Mg(11), one Mg(14), one Mg(2), one Mg(3), one Mg(5), one Mg(9), one Al(2), one Al(4), one Al(5), one Al(6), and one Al(8) atom. In the seventh Mg site, Mg(7) is bonded in a 4-coordinate geometry to one Mg(12), one Mg(15), one Mg(4), one Mg(9), one Au(1), one Al(1), one Al(4), one Al(7), and one Al(9) atom. In the eighth Mg site, Mg(8) is bonded in a 10-coordinate geometry to one Mg(1), one Mg(11), one Mg(12), one Mg(5), one Al(1), one Al(2), one Al(4), one Al(5), one Al(6), and one Al(7) atom. In the ninth Mg site, Mg(9) is bonded in a 13-coordinate geometry to one Mg(11), one Mg(13), one Mg(14), one Mg(3), one Mg(5), one Mg(6), one Mg(7), one Au(1), one Al(11), one Al(3), one Al(5), one Al(6), and one Al(9) atom. In the tenth Mg site, Mg(10) is bonded in a 5-coordinate geometry to one Mg(12), one Mg(15), one Mg(2), one Mg(6), one Al(10), one Al(3), one Al(4), one Al(7), and one Al(8) atom. In the eleventh Mg site, Mg(11) is bonded in a 5-coordinate geometry to one Mg(15), one Mg(2), one Mg(6), one Mg(8), one Mg(9), one Al(11), one Al(12), one Al(5), one Al(7), and one Al(8) atom. In the twelfth Mg site, Mg(12) is bonded in a 13-coordinate geometry to one Mg(10), one Mg(14), one Mg(15), one Mg(16), one Mg(3), one Mg(7), one Mg(8), one Au(1), one Al(10), one Al(12), one Al(4), one Al(6), and one Al(9) atom. In the thirteenth Mg site, Mg(13) is bonded in a 6-coordinate geometry to one Mg(1), one Mg(9), one Al(1), one Al(10), one Al(11), one Al(2), one Al(6), one Al(8), and one Al(9) atom. In the fourteenth Mg site, Mg(14) is bonded in a 4-coordinate geometry to one Mg(12), one Mg(4), one Mg(6), one Mg(9), one Au(1), one Al(1), one Al(10), one Al(11), one Al(6), and one Al(8) atom. In the fifteenth Mg site, Mg(15) is bonded in a 12-coordinate geometry to one Mg(10), one Mg(11), one Mg(12), one Mg(16), one Mg(2), one Mg(3), one Mg(7), one Al(10), one Al(11), one Al(2), one Al(7), and one Al(9) atom. In the sixteenth Mg site, Mg(16) is bonded in a 6-coordinate geometry to one Mg(12), one Mg(15), one Mg(2), one Au(1), one Al(1), one Al(12), one Al(2), one Al(6), and one Al(7) atom. Au(1) is bonded in a 11-coordinate geometry to one Mg(12), one Mg(14), one Mg(16), one Mg(3), one Mg(4), one Mg(5), one Mg(7), one Mg(9), one Al(1), one Al(10), and one Al(5) atom. There are twelve inequivalent Al sites. In the first Al site, Al(1) is bonded in a 11-coordinate geometry to one Mg(1), one Mg(13), one Mg(14), one Mg(16), one Mg(5), one Mg(7), one Mg(8), one Au(1), one Al(11), one Al(2), and one Al(4) atom. In the second Al site, Al(2) is bonded in a 11-coordinate geometry to one Mg(1), one Mg(13), one Mg(15), one Mg(16), one Mg(2), one Mg(5), one Mg(6), one Mg(8), one Al(1), one Al(10), and one Al(5) atom. In the third Al site, Al(3) is bonded in a 10-coordinate geometry to one Mg(1), one Mg(10), one Mg(2), one Mg(3), one Mg(4), one Mg(5), one Mg(9), one Al(12), one Al(6), and one Al(7) atom. In the fourth Al site, Al(4) is bonded in a 11-coordinate geometry to one Mg(1), one Mg(10), one Mg(12), one Mg(2), one Mg(3), one Mg(6), one Mg(7), one Mg(8), one Al(1), one Al(11), and one Al(6) atom. In the fifth Al site, Al(5) is bonded in a 1-coordinate geometry to one Mg(1), one Mg(11), one Mg(4), one Mg(6), one Mg(8), one Mg(9), one Au(1), one Al(10), one Al(2), and one Al(7) atom. In the sixth Al site, Al(6) is bonded in a 12-coordinate geometry to one Mg(1), one Mg(12), one Mg(13), one Mg(14), one Mg(16), one Mg(3), one Mg(6), one Mg(8), one Mg(9), one Al(3), one Al(4), and one Al(7) atom. In the seventh Al site, Al(7) is bonded in a 11-coordinate geometry to one Mg(1), one Mg(10), one Mg(11), one Mg(15), one Mg(16), one Mg(4), one Mg(7), one Mg(8), one Al(3), one Al(5), and one Al(6) atom. In the eighth Al site, Al(8) is bonded in a 11-coordinate geometry to one Mg(1), one Mg(10), one Mg(11), one Mg(13), one Mg(14), one Mg(4), one Mg(5), one Mg(6), one Al(10), one Al(12), and one Al(9) atom. In the ninth Al site, Al(9) is bonded in a 11-coordinate geometry to one Mg(1), one Mg(12), one Mg(13), one Mg(15), one Mg(3), one Mg(5), one Mg(7), one Mg(9), one Al(11), one Al(12), and one Al(8) atom. In the tenth Al site, Al(10) is bonded in a 11-coordinate geometry to one Mg(1), one Mg(10), one Mg(12), one Mg(13), one Mg(14), one Mg(15), one Mg(4), one Au(1), one Al(2), one Al(5), and one Al(8) atom. In the eleventh Al site, Al(11) is bonded in a 11-coordinate geometry to one Mg(1), one Mg(11), one Mg(13), one Mg(14), one Mg(15), one Mg(2), one Mg(3), one Mg(9), one Al(1), one Al(4), and one Al(9) atom. In the twelfth Al site, Al(12) is bonded in a 10-coordinate geometry to one Mg(1), one Mg(11), one Mg(12), one Mg(16), one Mg(2), one Mg(3), one Mg(4), one Al(3), one Al(8), and one Al(9) atom.
Mg16AuAl12 crystallizes in the triclinic P1 space group. There are sixteen inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 16-coordinate geometry to one Mg(13), one Mg(3), one Mg(4), one Mg(8), one Al(1), one Al(10), one Al(11), one Al(12), one Al(2), one Al(3), one Al(4), one Al(5), one Al(6), one Al(7), one Al(8), and one Al(9) atom. The Mg(1)-Mg(13) bond length is 3.16 Å. The Mg(1)-Mg(3) bond length is 3.28 Å. The Mg(1)-Mg(4) bond length is 3.13 Å. The Mg(1)-Mg(8) bond length is 3.20 Å. The Mg(1)-Al(1) bond length is 3.14 Å. The Mg(1)-Al(10) bond length is 3.27 Å. The Mg(1)-Al(11) bond length is 3.14 Å. The Mg(1)-Al(12) bond length is 3.12 Å. The Mg(1)-Al(2) bond length is 3.27 Å. The Mg(1)-Al(3) bond length is 3.08 Å. The Mg(1)-Al(4) bond length is 3.15 Å. The Mg(1)-Al(5) bond length is 3.29 Å. The Mg(1)-Al(6) bond length is 3.14 Å. The Mg(1)-Al(7) bond length is 3.19 Å. The Mg(1)-Al(8) bond length is 3.19 Å. The Mg(1)-Al(9) bond length is 3.17 Å. In the second Mg site, Mg(2) is bonded in a 12-coordinate geometry to one Mg(10), one Mg(11), one Mg(15), one Mg(16), one Mg(4), one Mg(5), one Mg(6), one Al(11), one Al(12), one Al(2), one Al(3), and one Al(4) atom. The Mg(2)-Mg(10) bond length is 3.13 Å. The Mg(2)-Mg(11) bond length is 3.10 Å. The Mg(2)-Mg(15) bond length is 3.08 Å. The Mg(2)-Mg(16) bond length is 3.11 Å. The Mg(2)-Mg(4) bond length is 3.04 Å. The Mg(2)-Mg(5) bond length is 3.10 Å. The Mg(2)-Mg(6) bond length is 3.05 Å. The Mg(2)-Al(11) bond length is 2.95 Å. The Mg(2)-Al(12) bond length is 3.12 Å. The Mg(2)-Al(2) bond length is 2.95 Å. The Mg(2)-Al(3) bond length is 3.14 Å. The Mg(2)-Al(4) bond length is 2.96 Å. In the third Mg site, Mg(3) is bonded in a 1-coordinate geometry to one Mg(1), one Mg(12), one Mg(15), one Mg(6), one Mg(9), one Au(1), one Al(11), one Al(12), one Al(3), one Al(4), one Al(6), and one Al(9) atom. The Mg(3)-Mg(12) bond length is 3.22 Å. The Mg(3)-Mg(15) bond length is 3.08 Å. The Mg(3)-Mg(6) bond length is 3.09 Å. The Mg(3)-Mg(9) bond length is 3.19 Å. The Mg(3)-Au(1) bond length is 3.03 Å. The Mg(3)-Al(11) bond length is 3.32 Å. The Mg(3)-Al(12) bond length is 3.00 Å. The Mg(3)-Al(3) bond length is 3.01 Å. The Mg(3)-Al(4) bond length is 3.35 Å. The Mg(3)-Al(6) bond length is 3.20 Å. The Mg(3)-Al(9) bond length is 3.16 Å. In the fourth Mg site, Mg(4) is bonded in a 11-coordinate geometry to one Mg(1), one Mg(14), one Mg(2), one Mg(7), one Au(1), one Al(10), one Al(12), one Al(3), one Al(5), one Al(7), and one Al(8) atom. The Mg(4)-Mg(14) bond length is 3.03 Å. The Mg(4)-Mg(7) bond length is 3.04 Å. The Mg(4)-Au(1) bond length is 3.01 Å. The Mg(4)-Al(10) bond length is 3.04 Å. The Mg(4)-Al(12) bond length is 3.07 Å. The Mg(4)-Al(3) bond length is 3.03 Å. The Mg(4)-Al(5) bond length is 3.09 Å. The Mg(4)-Al(7) bond length is 3.10 Å. The Mg(4)-Al(8) bond length is 3.08 Å. In the fifth Mg site, Mg(5) is bonded in a 6-coordinate geometry to one Mg(2), one Mg(6), one Mg(8), one Mg(9), one Au(1), one Al(1), one Al(2), one Al(3), one Al(8), and one Al(9) atom. The Mg(5)-Mg(6) bond length is 3.28 Å. The Mg(5)-Mg(8) bond length is 3.05 Å. The Mg(5)-Mg(9) bond length is 3.06 Å. The Mg(5)-Au(1) bond length is 3.18 Å. The Mg(5)-Al(1) bond length is 3.08 Å. The Mg(5)-Al(2) bond length is 3.01 Å. The Mg(5)-Al(3) bond length is 2.85 Å. The Mg(5)-Al(8) bond length is 3.10 Å. The Mg(5)-Al(9) bond length is 3.03 Å. In the sixth Mg site, Mg(6) is bonded in a 12-coordinate geometry to one Mg(10), one Mg(11), one Mg(14), one Mg(2), one Mg(3), one Mg(5), one Mg(9), one Al(2), one Al(4), one Al(5), one Al(6), and one Al(8) atom. The Mg(6)-Mg(10) bond length is 3.10 Å. The Mg(6)-Mg(11) bond length is 3.14 Å. The Mg(6)-Mg(14) bond length is 3.10 Å. The Mg(6)-Mg(9) bond length is 3.13 Å. The Mg(6)-Al(2) bond length is 2.97 Å. The Mg(6)-Al(4) bond length is 3.13 Å. The Mg(6)-Al(5) bond length is 2.94 Å. The Mg(6)-Al(6) bond length is 3.26 Å. The Mg(6)-Al(8) bond length is 2.88 Å. In the seventh Mg site, Mg(7) is bonded in a 4-coordinate geometry to one Mg(12), one Mg(15), one Mg(4), one Mg(9), one Au(1), one Al(1), one Al(4), one Al(7), and one Al(9) atom. The Mg(7)-Mg(12) bond length is 3.16 Å. The Mg(7)-Mg(15) bond length is 3.09 Å. The Mg(7)-Mg(9) bond length is 3.13 Å. The Mg(7)-Au(1) bond length is 2.84 Å. The Mg(7)-Al(1) bond length is 2.96 Å. The Mg(7)-Al(4) bond length is 2.97 Å. The Mg(7)-Al(7) bond length is 3.22 Å. The Mg(7)-Al(9) bond length is 2.88 Å. In the eighth Mg site, Mg(8) is bonded in a 10-coordinate geometry to one Mg(1), one Mg(11), one Mg(12), one Mg(5), one Al(1), one Al(2), one Al(4), one Al(5), one Al(6), and one Al(7) atom. The Mg(8)-Mg(11) bond length is 3.06 Å. The Mg(8)-Mg(12) bond length is 3.05 Å. The Mg(8)-Al(1) bond length is 3.05 Å. The Mg(8)-Al(2) bond length is 3.07 Å. The Mg(8)-Al(4) bond length is 3.15 Å. The Mg(8)-Al(5) bond length is 3.13 Å. The Mg(8)-Al(6) bond length is 3.13 Å. The Mg(8)-Al(7) bond length is 3.08 Å. In the ninth Mg site, Mg(9) is bonded in a 13-coordinate geometry to one Mg(11), one Mg(13), one Mg(14), one Mg(3), one Mg(5), one Mg(6), one Mg(7), one Au(1), one Al(11), one Al(3), one Al(5), one Al(6), and one Al(9) atom. The Mg(9)-Mg(11) bond length is 3.18 Å. The Mg(9)-Mg(13) bond length is 3.06 Å. The Mg(9)-Mg(14) bond length is 3.20 Å. The Mg(9)-Au(1) bond length is 3.14 Å. The Mg(9)-Al(11) bond length is 3.23 Å. The Mg(9)-Al(3) bond length is 3.02 Å. The Mg(9)-Al(5) bond length is 2.89 Å. The Mg(9)-Al(6) bond length is 3.00 Å. The Mg(9)-Al(9) bond length is 3.16 Å. In the tenth Mg site, Mg(10) is bonded in a 5-coordinate geometry to one Mg(12), one Mg(15), one Mg(2), one Mg(6), one Al(10), one Al(3), one Al(4), one Al(7), and one Al(8) atom. The Mg(10)-Mg(12) bond length is 3.18 Å. The Mg(10)-Mg(15) bond length is 3.18 Å. The Mg(10)-Al(10) bond length is 3.03 Å. The Mg(10)-Al(3) bond length is 2.94 Å. The Mg(10)-Al(4) bond length is 2.89 Å. The Mg(10)-Al(7) bond length is 2.99 Å. The Mg(10)-Al(8) bond length is 3.07 Å. In the eleventh Mg site, Mg(11) is bonded in a 5-coordinate geometry to one Mg(15), one Mg(2), one Mg(6), one Mg(8), one Mg(9), one Al(11), one Al(12), one Al(5), one Al(7), and one Al(8) atom. The Mg(11)-Mg(15) bond length is 3.08 Å. The Mg(11)-Al(11) bond length is 2.91 Å. The Mg(11)-Al(12) bond length is 2.93 Å. The Mg(11)-Al(5) bond length is 3.04 Å. The Mg(11)-Al(7) bond length is 3.12 Å. The Mg(11)-Al(8) bond length is 3.01 Å. In the twelfth Mg site, Mg(12) is bonded in a 13-coordinate geometry to one Mg(10), one Mg(14), one Mg(15), one Mg(16), one Mg(3), one Mg(7), one Mg(8), one Au(1), one Al(10), one Al(12), one Al(4), one Al(6), and one Al(9) atom. The Mg(12)-Mg(14) bond length is 3.11 Å. The Mg(12)-Mg(15) bond length is 3.13 Å. The Mg(12)-Mg(16) bond length is 3.05 Å. The Mg(12)-Au(1) bond length is 3.10 Å. The Mg(12)-Al(10) bond length is 2.87 Å. The Mg(12)-Al(12) bond length is 3.03 Å. The Mg(12)-Al(4) bond length is 3.25 Å. The Mg(12)-Al(6) bond length is 3.20 Å. The Mg(12)-Al(9) bond length is 3.00 Å. In the thirteenth Mg site, Mg(13) is bonded in a 6-coordinate geometry to one Mg(1), one Mg(9), one Al(1), one Al(10), one Al(11), one Al(2), one Al(6), one Al(8), and one Al(9) atom. The Mg(13)-Al(1) bond length is 3.05 Å. The Mg(13)-Al(10) bond length is 3.15 Å. The Mg(13)-Al(11) bond length is 3.11 Å. The Mg(13)-Al(2) bond length is 3.13 Å. The Mg(13)-Al(6) bond length is 3.37 Å. The Mg(13)-Al(8) bond length is 3.08 Å. The Mg(13)-Al(9) bond length is 3.12 Å. In the fourteenth Mg site, Mg(14) is bonded in a 4-coordinate geometry to one Mg(12), one Mg(4), one Mg(6), one Mg(9), one Au(1), one Al(1), one Al(10), one Al(11), one Al(6), and one Al(8) atom. The Mg(14)-Au(1) bond length is 2.87 Å. The Mg(14)-Al(1) bond length is 2.95 Å. The Mg(14)-Al(10) bond length is 3.18 Å. The Mg(14)-Al(11) bond length is 2.95 Å. The Mg(14)-Al(6) bond length is 2.86 Å. The Mg(14)-Al(8) bond length is 3.20 Å. In the fifteenth Mg site, Mg(15) is bonded in a 12-coordinate geometry to one Mg(10), one Mg(11), one Mg(12), one Mg(16), one Mg(2), one Mg(3), one Mg(7), one Al(10), one Al(11), one Al(2), one Al(7), and one Al(9) atom. The Mg(15)-Mg(16) bond length is 3.28 Å. The Mg(15)-Al(10) bond length is 2.93 Å. The Mg(15)-Al(11) bond length is 3.16 Å. The Mg(15)-Al(2) bond length is 2.97 Å. The Mg(15)-Al(7) bond length is 2.88 Å. The Mg(15)-Al(9) bond length is 3.26 Å. In the sixteenth Mg site, Mg(16) is bonded in a 6-coordinate geometry to one Mg(12), one Mg(15), one Mg(2), one Au(1), one Al(1), one Al(12), one Al(2), one Al(6), and one Al(7) atom. The Mg(16)-Au(1) bond length is 3.18 Å. The Mg(16)-Al(1) bond length is 3.05 Å. The Mg(16)-Al(12) bond length is 2.85 Å. The Mg(16)-Al(2) bond length is 3.00 Å. The Mg(16)-Al(6) bond length is 3.06 Å. The Mg(16)-Al(7) bond length is 3.08 Å. Au(1) is bonded in a 11-coordinate geometry to one Mg(12), one Mg(14), one Mg(16), one Mg(3), one Mg(4), one Mg(5), one Mg(7), one Mg(9), one Al(1), one Al(10), and one Al(5) atom. The Au(1)-Al(1) bond length is 2.70 Å. The Au(1)-Al(10) bond length is 2.73 Å. The Au(1)-Al(5) bond length is 2.75 Å. There are twelve inequivalent Al sites. In the first Al site, Al(1) is bonded in a 11-coordinate geometry to one Mg(1), one Mg(13), one Mg(14), one Mg(16), one Mg(5), one Mg(7), one Mg(8), one Au(1), one Al(11), one Al(2), and one Al(4) atom. The Al(1)-Al(11) bond length is 2.76 Å. The Al(1)-Al(2) bond length is 2.69 Å. The Al(1)-Al(4) bond length is 2.74 Å. In the second Al site, Al(2) is bonded in a 11-coordinate geometry to one Mg(1), one Mg(13), one Mg(15), one Mg(16), one Mg(2), one Mg(5), one Mg(6), one Mg(8), one Al(1), one Al(10), and one Al(5) atom. The Al(2)-Al(10) bond length is 2.77 Å. The Al(2)-Al(5) bond length is 2.72 Å. In the third Al site, Al(3) is bonded in a 10-coordinate geometry to one Mg(1), one Mg(10), one Mg(2), one Mg(3), one Mg(4), one Mg(5), one Mg(9), one Al(12), one Al(6), and one Al(7) atom. The Al(3)-Al(12) bond length is 2.68 Å. The Al(3)-Al(6) bond length is 2.73 Å. The Al(3)-Al(7) bond length is 2.72 Å. In the fourth Al site, Al(4) is bonded in a 11-coordinate geometry to one Mg(1), one Mg(10), one Mg(12), one Mg(2), one Mg(3), one Mg(6), one Mg(7), one Mg(8), one Al(1), one Al(11), and one Al(6) atom. The Al(4)-Al(11) bond length is 2.70 Å. The Al(4)-Al(6) bond length is 2.66 Å. In the fifth Al site, Al(5) is bonded in a 1-coordinate geometry to one Mg(1), one Mg(11), one Mg(4), one Mg(6), one Mg(8), one Mg(9), one Au(1), one Al(10), one Al(2), and one Al(7) atom. The Al(5)-Al(10) bond length is 2.75 Å. The Al(5)-Al(7) bond length is 2.70 Å. In the sixth Al site, Al(6) is bonded in a 12-coordinate geometry to one Mg(1), one Mg(12), one Mg(13), one Mg(14), one Mg(16), one Mg(3), one Mg(6), one Mg(8), one Mg(9), one Al(3), one Al(4), and one Al(7) atom. The Al(6)-Al(7) bond length is 2.75 Å. In the seventh Al site, Al(7) is bonded in a 11-coordinate geometry to one Mg(1), one Mg(10), one Mg(11), one Mg(15), one Mg(16), one Mg(4), one Mg(7), one Mg(8), one Al(3), one Al(5), and one Al(6) atom. In the eighth Al site, Al(8) is bonded in a 11-coordinate geometry to one Mg(1), one Mg(10), one Mg(11), one Mg(13), one Mg(14), one Mg(4), one Mg(5), one Mg(6), one Al(10), one Al(12), and one Al(9) atom. The Al(8)-Al(10) bond length is 2.69 Å. The Al(8)-Al(12) bond length is 2.72 Å. The Al(8)-Al(9) bond length is 2.76 Å. In the ninth Al site, Al(9) is bonded in a 11-coordinate geometry to one Mg(1), one Mg(12), one Mg(13), one Mg(15), one Mg(3), one Mg(5), one Mg(7), one Mg(9), one Al(11), one Al(12), and one Al(8) atom. The Al(9)-Al(11) bond length is 2.68 Å. The Al(9)-Al(12) bond length is 2.71 Å. In the tenth Al site, Al(10) is bonded in a 11-coordinate geometry to one Mg(1), one Mg(10), one Mg(12), one Mg(13), one Mg(14), one Mg(15), one Mg(4), one Au(1), one Al(2), one Al(5), and one Al(8) atom. In the eleventh Al site, Al(11) is bonded in a 11-coordinate geometry to one Mg(1), one Mg(11), one Mg(13), one Mg(14), one Mg(15), one Mg(2), one Mg(3), one Mg(9), one Al(1), one Al(4), and one Al(9) atom. In the twelfth Al site, Al(12) is bonded in a 10-coordinate geometry to one Mg(1), one Mg(11), one Mg(12), one Mg(16), one Mg(2), one Mg(3), one Mg(4), one Al(3), one Al(8), and one Al(9) atom.