Mg2Zn crystallizes in the hexagonal P-62m 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 Zn(1) atoms to form distorted MgMg8Zn4 cuboctahedra that share corners with eighteen equivalent Mg(1)Mg8Zn4 cuboctahedra, edges with four equivalent Mg(2)Mg6Zn6 cuboctahedra, edges with six equivalent Mg(1)Mg8Zn4 cuboctahedra, edges with eight equivalent Zn(1)Mg9Zn3 cuboctahedra, faces with four equivalent Mg(2)Mg6Zn6 cuboctahedra, faces with eight equivalent Mg(1)Mg8Zn4 cuboctahedra, and faces with eight equivalent Zn(1)Mg9Zn3 cuboctahedra. In the second Mg site, Mg(2) is bonded to six equivalent Mg(1) and six equivalent Zn(1) atoms to form distorted MgMg6Zn6 cuboctahedra that share corners with eighteen equivalent Zn(1)Mg9Zn3 cuboctahedra, edges with six equivalent Mg(2)Mg6Zn6 cuboctahedra, edges with twelve equivalent Mg(1)Mg8Zn4 cuboctahedra, faces with two equivalent Mg(2)Mg6Zn6 cuboctahedra, faces with six equivalent Zn(1)Mg9Zn3 cuboctahedra, and faces with twelve equivalent Mg(1)Mg8Zn4 cuboctahedra. Zn(1) is bonded to three equivalent Mg(2), six equivalent Mg(1), and three equivalent Zn(1) atoms to form distorted ZnMg9Zn3 cuboctahedra that share corners with nine equivalent Mg(2)Mg6Zn6 cuboctahedra, corners with nine equivalent Zn(1)Mg9Zn3 cuboctahedra, edges with six equivalent Zn(1)Mg9Zn3 cuboctahedra, edges with twelve equivalent Mg(1)Mg8Zn4 cuboctahedra, faces with three equivalent Mg(2)Mg6Zn6 cuboctahedra, faces with five equivalent Zn(1)Mg9Zn3 cuboctahedra, and faces with twelve equivalent Mg(1)Mg8Zn4 cuboctahedra.
Mg2Zn crystallizes in the hexagonal P-62m 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 Zn(1) atoms to form distorted MgMg8Zn4 cuboctahedra that share corners with eighteen equivalent Mg(1)Mg8Zn4 cuboctahedra, edges with four equivalent Mg(2)Mg6Zn6 cuboctahedra, edges with six equivalent Mg(1)Mg8Zn4 cuboctahedra, edges with eight equivalent Zn(1)Mg9Zn3 cuboctahedra, faces with four equivalent Mg(2)Mg6Zn6 cuboctahedra, faces with eight equivalent Mg(1)Mg8Zn4 cuboctahedra, and faces with eight equivalent Zn(1)Mg9Zn3 cuboctahedra. Both Mg(1)-Mg(2) bond lengths are 3.07 Å. There are four shorter (2.99 Å) and two longer (3.11 Å) Mg(1)-Mg(1) bond lengths. All Mg(1)-Zn(1) bond lengths are 3.03 Å. In the second Mg site, Mg(2) is bonded to six equivalent Mg(1) and six equivalent Zn(1) atoms to form distorted MgMg6Zn6 cuboctahedra that share corners with eighteen equivalent Zn(1)Mg9Zn3 cuboctahedra, edges with six equivalent Mg(2)Mg6Zn6 cuboctahedra, edges with twelve equivalent Mg(1)Mg8Zn4 cuboctahedra, faces with two equivalent Mg(2)Mg6Zn6 cuboctahedra, faces with six equivalent Zn(1)Mg9Zn3 cuboctahedra, and faces with twelve equivalent Mg(1)Mg8Zn4 cuboctahedra. All Mg(2)-Zn(1) bond lengths are 3.03 Å. Zn(1) is bonded to three equivalent Mg(2), six equivalent Mg(1), and three equivalent Zn(1) atoms to form distorted ZnMg9Zn3 cuboctahedra that share corners with nine equivalent Mg(2)Mg6Zn6 cuboctahedra, corners with nine equivalent Zn(1)Mg9Zn3 cuboctahedra, edges with six equivalent Zn(1)Mg9Zn3 cuboctahedra, edges with twelve equivalent Mg(1)Mg8Zn4 cuboctahedra, faces with three equivalent Mg(2)Mg6Zn6 cuboctahedra, faces with five equivalent Zn(1)Mg9Zn3 cuboctahedra, and faces with twelve equivalent Mg(1)Mg8Zn4 cuboctahedra. All Zn(1)-Zn(1) bond lengths are 3.03 Å.