Mg2Zn11 crystallizes in the cubic Pm-3 space group. Mg(1) is bonded in a 12-coordinate geometry to four equivalent Zn(3), four equivalent Zn(4), and six equivalent Zn(5) atoms. There are five inequivalent Zn sites. In the first Zn site, Zn(1) is bonded to twelve equivalent Zn(5) atoms to form face-sharing ZnZn12 cuboctahedra. In the second Zn site, Zn(2) is bonded in a 10-coordinate geometry to two equivalent Zn(3), four equivalent Zn(2), and four equivalent Zn(4) atoms. In the third Zn site, Zn(3) is bonded in a 13-coordinate geometry to four equivalent Mg(1), one Zn(3), two equivalent Zn(2), two equivalent Zn(5), and four equivalent Zn(4) atoms. In the fourth Zn site, Zn(4) is bonded in a 9-coordinate geometry to three equivalent Mg(1), three equivalent Zn(2), three equivalent Zn(3), and three equivalent Zn(5) atoms. In the fifth Zn site, Zn(5) is bonded to three equivalent Mg(1), one Zn(1), one Zn(3), two equivalent Zn(4), and five equivalent Zn(5) atoms to form distorted ZnMg3Zn9 cuboctahedra that share corners with six equivalent Zn(5)Mg3Zn9 cuboctahedra,  an edgeedge with one Zn(5)Mg3Zn9 cuboctahedra,  a faceface with one Zn(1)Zn12 cuboctahedra, and faces with eleven equivalent Zn(5)Mg3Zn9 cuboctahedra.
Mg2Zn11 crystallizes in the cubic Pm-3 space group. Mg(1) is bonded in a 12-coordinate geometry to four equivalent Zn(3), four equivalent Zn(4), and six equivalent Zn(5) atoms. There are two shorter (2.88 Å) and two longer (3.30 Å) Mg(1)-Zn(3) bond lengths. All Mg(1)-Zn(4) bond lengths are 3.08 Å. There are four shorter (2.91 Å) and two longer (2.93 Å) Mg(1)-Zn(5) bond lengths. There are five inequivalent Zn sites. In the first Zn site, Zn(1) is bonded to twelve equivalent Zn(5) atoms to form face-sharing ZnZn12 cuboctahedra. All Zn(1)-Zn(5) bond lengths are 2.58 Å. In the second Zn site, Zn(2) is bonded in a 10-coordinate geometry to two equivalent Zn(3), four equivalent Zn(2), and four equivalent Zn(4) atoms. Both Zn(2)-Zn(3) bond lengths are 2.65 Å. All Zn(2)-Zn(2) bond lengths are 2.73 Å. All Zn(2)-Zn(4) bond lengths are 2.60 Å. In the third Zn site, Zn(3) is bonded in a 13-coordinate geometry to four equivalent Mg(1), one Zn(3), two equivalent Zn(2), two equivalent Zn(5), and four equivalent Zn(4) atoms. The Zn(3)-Zn(3) bond length is 2.71 Å. Both Zn(3)-Zn(5) bond lengths are 2.51 Å. All Zn(3)-Zn(4) bond lengths are 3.04 Å. In the fourth Zn site, Zn(4) is bonded in a 9-coordinate geometry to three equivalent Mg(1), three equivalent Zn(2), three equivalent Zn(3), and three equivalent Zn(5) atoms. All Zn(4)-Zn(5) bond lengths are 2.59 Å. In the fifth Zn site, Zn(5) is bonded to three equivalent Mg(1), one Zn(1), one Zn(3), two equivalent Zn(4), and five equivalent Zn(5) atoms to form distorted ZnMg3Zn9 cuboctahedra that share corners with six equivalent Zn(5)Mg3Zn9 cuboctahedra,  an edgeedge with one Zn(5)Mg3Zn9 cuboctahedra,  a faceface with one Zn(1)Zn12 cuboctahedra, and faces with eleven equivalent Zn(5)Mg3Zn9 cuboctahedra. There is one shorter (2.65 Å) and four longer (2.73 Å) Zn(5)-Zn(5) bond lengths.