MgZn2 crystallizes in the orthorhombic Cmcm space group. Mg(1) is bonded to six equivalent Mg(1), two equivalent Zn(2), and four equivalent Zn(1) atoms to form distorted MgMg6Zn6 cuboctahedra that share corners with six equivalent Mg(1)Mg6Zn6 cuboctahedra, corners with six equivalent Zn(2)Mg2Zn10 cuboctahedra, corners with six equivalent Zn(1)Mg4Zn8 cuboctahedra, edges with three equivalent Zn(1)Mg4Zn8 cuboctahedra, edges with four equivalent Mg(1)Mg6Zn6 cuboctahedra, edges with eleven equivalent Zn(2)Mg2Zn10 cuboctahedra, faces with four equivalent Zn(2)Mg2Zn10 cuboctahedra, faces with eight equivalent Mg(1)Mg6Zn6 cuboctahedra, and faces with eight equivalent Zn(1)Mg4Zn8 cuboctahedra. There are two inequivalent Zn sites. In the first Zn site, Zn(1) is bonded to four equivalent Mg(1), two equivalent Zn(1), and six equivalent Zn(2) atoms to form distorted ZnMg4Zn8 cuboctahedra that share corners with six equivalent Mg(1)Mg6Zn6 cuboctahedra, corners with six equivalent Zn(2)Mg2Zn10 cuboctahedra, corners with six equivalent Zn(1)Mg4Zn8 cuboctahedra, edges with three equivalent Mg(1)Mg6Zn6 cuboctahedra, edges with seven equivalent Zn(2)Mg2Zn10 cuboctahedra, edges with eight equivalent Zn(1)Mg4Zn8 cuboctahedra, faces with six equivalent Zn(2)Mg2Zn10 cuboctahedra, faces with six equivalent Zn(1)Mg4Zn8 cuboctahedra, and faces with eight equivalent Mg(1)Mg6Zn6 cuboctahedra. In the second Zn site, Zn(2) is bonded to two equivalent Mg(1), four equivalent Zn(2), and six equivalent Zn(1) atoms to form distorted ZnMg2Zn10 cuboctahedra that share corners with six equivalent Mg(1)Mg6Zn6 cuboctahedra, corners with six equivalent Zn(2)Mg2Zn10 cuboctahedra, corners with six equivalent Zn(1)Mg4Zn8 cuboctahedra, edges with seven equivalent Zn(1)Mg4Zn8 cuboctahedra, edges with eleven equivalent Mg(1)Mg6Zn6 cuboctahedra, faces with four equivalent Mg(1)Mg6Zn6 cuboctahedra, faces with six equivalent Zn(1)Mg4Zn8 cuboctahedra, and faces with ten equivalent Zn(2)Mg2Zn10 cuboctahedra.
MgZn2 crystallizes in the orthorhombic Cmcm space group. Mg(1) is bonded to six equivalent Mg(1), two equivalent Zn(2), and four equivalent Zn(1) atoms to form distorted MgMg6Zn6 cuboctahedra that share corners with six equivalent Mg(1)Mg6Zn6 cuboctahedra, corners with six equivalent Zn(2)Mg2Zn10 cuboctahedra, corners with six equivalent Zn(1)Mg4Zn8 cuboctahedra, edges with three equivalent Zn(1)Mg4Zn8 cuboctahedra, edges with four equivalent Mg(1)Mg6Zn6 cuboctahedra, edges with eleven equivalent Zn(2)Mg2Zn10 cuboctahedra, faces with four equivalent Zn(2)Mg2Zn10 cuboctahedra, faces with eight equivalent Mg(1)Mg6Zn6 cuboctahedra, and faces with eight equivalent Zn(1)Mg4Zn8 cuboctahedra. All Mg(1)-Mg(1) bond lengths are 2.97 Å. Both Mg(1)-Zn(2) bond lengths are 2.89 Å. There are two shorter (2.86 Å) and two longer (3.00 Å) Mg(1)-Zn(1) bond lengths. There are two inequivalent Zn sites. In the first Zn site, Zn(1) is bonded to four equivalent Mg(1), two equivalent Zn(1), and six equivalent Zn(2) atoms to form distorted ZnMg4Zn8 cuboctahedra that share corners with six equivalent Mg(1)Mg6Zn6 cuboctahedra, corners with six equivalent Zn(2)Mg2Zn10 cuboctahedra, corners with six equivalent Zn(1)Mg4Zn8 cuboctahedra, edges with three equivalent Mg(1)Mg6Zn6 cuboctahedra, edges with seven equivalent Zn(2)Mg2Zn10 cuboctahedra, edges with eight equivalent Zn(1)Mg4Zn8 cuboctahedra, faces with six equivalent Zn(2)Mg2Zn10 cuboctahedra, faces with six equivalent Zn(1)Mg4Zn8 cuboctahedra, and faces with eight equivalent Mg(1)Mg6Zn6 cuboctahedra. Both Zn(1)-Zn(1) bond lengths are 2.97 Å. There are two shorter (2.75 Å) and four longer (2.93 Å) Zn(1)-Zn(2) bond lengths. In the second Zn site, Zn(2) is bonded to two equivalent Mg(1), four equivalent Zn(2), and six equivalent Zn(1) atoms to form distorted ZnMg2Zn10 cuboctahedra that share corners with six equivalent Mg(1)Mg6Zn6 cuboctahedra, corners with six equivalent Zn(2)Mg2Zn10 cuboctahedra, corners with six equivalent Zn(1)Mg4Zn8 cuboctahedra, edges with seven equivalent Zn(1)Mg4Zn8 cuboctahedra, edges with eleven equivalent Mg(1)Mg6Zn6 cuboctahedra, faces with four equivalent Mg(1)Mg6Zn6 cuboctahedra, faces with six equivalent Zn(1)Mg4Zn8 cuboctahedra, and faces with ten equivalent Zn(2)Mg2Zn10 cuboctahedra. There are two shorter (2.77 Å) and two longer (2.97 Å) Zn(2)-Zn(2) bond lengths.