Mg2Ga crystallizes in the trigonal R32 space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Mg(2), six equivalent Mg(1), and four equivalent Ga(1) atoms to form distorted MgMg8Ga4 cuboctahedra that share corners with eighteen equivalent Mg(1)Mg8Ga4 cuboctahedra, edges with four equivalent Mg(2)Mg6Ga6 cuboctahedra, edges with six equivalent Mg(1)Mg8Ga4 cuboctahedra, faces with four equivalent Mg(2)Mg6Ga6 cuboctahedra, and faces with eight equivalent Mg(1)Mg8Ga4 cuboctahedra. In the second Mg site, Mg(2) is bonded to six equivalent Mg(1) and six equivalent Ga(1) atoms to form MgMg6Ga6 cuboctahedra that share corners with six equivalent Mg(2)Mg6Ga6 cuboctahedra, edges with six equivalent Mg(2)Mg6Ga6 cuboctahedra, edges with twelve equivalent Mg(1)Mg8Ga4 cuboctahedra, and faces with twelve equivalent Mg(1)Mg8Ga4 cuboctahedra. Ga(1) is bonded in a 9-coordinate geometry to three equivalent Mg(2) and six equivalent Mg(1) atoms.
Mg2Ga crystallizes in the trigonal R32 space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Mg(2), six equivalent Mg(1), and four equivalent Ga(1) atoms to form distorted MgMg8Ga4 cuboctahedra that share corners with eighteen equivalent Mg(1)Mg8Ga4 cuboctahedra, edges with four equivalent Mg(2)Mg6Ga6 cuboctahedra, edges with six equivalent Mg(1)Mg8Ga4 cuboctahedra, faces with four equivalent Mg(2)Mg6Ga6 cuboctahedra, and faces with eight equivalent Mg(1)Mg8Ga4 cuboctahedra. Both Mg(1)-Mg(2) bond lengths are 3.02 Å. There are two shorter (3.05 Å) and four longer (3.11 Å) Mg(1)-Mg(1) bond lengths. There are two shorter (2.98 Å) and two longer (3.03 Å) Mg(1)-Ga(1) bond lengths. In the second Mg site, Mg(2) is bonded to six equivalent Mg(1) and six equivalent Ga(1) atoms to form MgMg6Ga6 cuboctahedra that share corners with six equivalent Mg(2)Mg6Ga6 cuboctahedra, edges with six equivalent Mg(2)Mg6Ga6 cuboctahedra, edges with twelve equivalent Mg(1)Mg8Ga4 cuboctahedra, and faces with twelve equivalent Mg(1)Mg8Ga4 cuboctahedra. All Mg(2)-Ga(1) bond lengths are 3.09 Å. Ga(1) is bonded in a 9-coordinate geometry to three equivalent Mg(2) and six equivalent Mg(1) atoms.