Mg2Ga5 crystallizes in the tetragonal I4/mmm space group. Mg(1) is bonded in a 10-coordinate geometry to two equivalent Ga(2) and eight equivalent Ga(1) atoms. There are two inequivalent Ga sites. In the first Ga site, Ga(1) is bonded in a 8-coordinate geometry to four equivalent Mg(1), one Ga(2), and three equivalent Ga(1) atoms. In the second Ga site, Ga(2) is bonded in a 9-coordinate geometry to four equivalent Mg(1), one Ga(2), and four equivalent Ga(1) atoms.
Mg2Ga5 crystallizes in the tetragonal I4/mmm space group. Mg(1) is bonded in a 10-coordinate geometry to two equivalent Ga(2) and eight equivalent Ga(1) atoms. Both Mg(1)-Ga(2) bond lengths are 2.84 Å. There are four shorter (2.87 Å) and four longer (2.95 Å) Mg(1)-Ga(1) bond lengths. There are two inequivalent Ga sites. In the first Ga site, Ga(1) is bonded in a 8-coordinate geometry to four equivalent Mg(1), one Ga(2), and three equivalent Ga(1) atoms. The Ga(1)-Ga(2) bond length is 2.67 Å. There is one shorter (2.57 Å) and two longer (2.63 Å) Ga(1)-Ga(1) bond lengths. In the second Ga site, Ga(2) is bonded in a 9-coordinate geometry to four equivalent Mg(1), one Ga(2), and four equivalent Ga(1) atoms. The Ga(2)-Ga(2) bond length is 2.91 Å.