Mg3Au crystallizes in the trigonal P-3c1 space group. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 3-coordinate geometry to three equivalent Au(1) atoms. In the second Mg site, Mg(3) is bonded in a distorted trigonal planar geometry to three equivalent Au(1) atoms. In the third Mg site, Mg(2) is bonded in a trigonal planar geometry to three equivalent Au(1) atoms. Au(1) is bonded in a 9-coordinate geometry to one Mg(2), two equivalent Mg(3), and six equivalent Mg(1) atoms.
Mg3Au crystallizes in the trigonal P-3c1 space group. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 3-coordinate geometry to three equivalent Au(1) atoms. There are two shorter (2.80 Å) and one longer (2.96 Å) Mg(1)-Au(1) bond length. In the second Mg site, Mg(3) is bonded in a distorted trigonal planar geometry to three equivalent Au(1) atoms. All Mg(3)-Au(1) bond lengths are 2.69 Å. In the third Mg site, Mg(2) is bonded in a trigonal planar geometry to three equivalent Au(1) atoms. All Mg(2)-Au(1) bond lengths are 2.71 Å. Au(1) is bonded in a 9-coordinate geometry to one Mg(2), two equivalent Mg(3), and six equivalent Mg(1) atoms.