Mg3Zn1 crystallizes in the orthorhombic Imm2 space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Mg(1), six equivalent Mg(2), and four equivalent Zn(1) atoms to form distorted MgMg8Zn4 cuboctahedra that share corners with fourteen equivalent Mg(1)Mg8Zn4 cuboctahedra, edges with two equivalent Mg(1)Mg8Zn4 cuboctahedra, edges with twelve equivalent Mg(2)Mg9Zn3 cuboctahedra, faces with two equivalent Mg(1)Mg8Zn4 cuboctahedra, and faces with twelve equivalent Mg(2)Mg9Zn3 cuboctahedra. In the second Mg site, Mg(2) is bonded to three equivalent Mg(1), six equivalent Mg(2), and three equivalent Zn(1) atoms to form distorted MgMg9Zn3 cuboctahedra that share corners with eighteen equivalent Mg(2)Mg9Zn3 cuboctahedra, edges with six equivalent Mg(1)Mg8Zn4 cuboctahedra, edges with six equivalent Mg(2)Mg9Zn3 cuboctahedra, faces with six equivalent Mg(1)Mg8Zn4 cuboctahedra, and faces with eight equivalent Mg(2)Mg9Zn3 cuboctahedra. Zn(1) is bonded in a 10-coordinate geometry to four equivalent Mg(1) and six equivalent Mg(2) atoms.
Mg3Zn1 crystallizes in the orthorhombic Imm2 space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Mg(1), six equivalent Mg(2), and four equivalent Zn(1) atoms to form distorted MgMg8Zn4 cuboctahedra that share corners with fourteen equivalent Mg(1)Mg8Zn4 cuboctahedra, edges with two equivalent Mg(1)Mg8Zn4 cuboctahedra, edges with twelve equivalent Mg(2)Mg9Zn3 cuboctahedra, faces with two equivalent Mg(1)Mg8Zn4 cuboctahedra, and faces with twelve equivalent Mg(2)Mg9Zn3 cuboctahedra. Both Mg(1)-Mg(1) bond lengths are 3.13 Å. There are two shorter (3.03 Å) and four longer (3.12 Å) Mg(1)-Mg(2) bond lengths. There are two shorter (2.98 Å) and two longer (3.11 Å) Mg(1)-Zn(1) bond lengths. In the second Mg site, Mg(2) is bonded to three equivalent Mg(1), six equivalent Mg(2), and three equivalent Zn(1) atoms to form distorted MgMg9Zn3 cuboctahedra that share corners with eighteen equivalent Mg(2)Mg9Zn3 cuboctahedra, edges with six equivalent Mg(1)Mg8Zn4 cuboctahedra, edges with six equivalent Mg(2)Mg9Zn3 cuboctahedra, faces with six equivalent Mg(1)Mg8Zn4 cuboctahedra, and faces with eight equivalent Mg(2)Mg9Zn3 cuboctahedra. There are four shorter (3.05 Å) and two longer (3.13 Å) Mg(2)-Mg(2) bond lengths. There are two shorter (3.01 Å) and one longer (3.12 Å) Mg(2)-Zn(1) bond length. Zn(1) is bonded in a 10-coordinate geometry to four equivalent Mg(1) and six equivalent Mg(2) atoms.