Mg14ZrSb crystallizes in the hexagonal P-6m2 space group. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Mg(4), four equivalent Mg(1), four equivalent Mg(3), and two equivalent Zr(1) atoms to form MgMg10Zr2 cuboctahedra that share corners with four equivalent Sb(1)Mg12 cuboctahedra, corners with six equivalent Mg(1)Mg10Zr2 cuboctahedra, corners with eight equivalent Mg(2)Mg10Sb2 cuboctahedra, edges with two equivalent Zr(1)Mg12 cuboctahedra, edges with four equivalent Mg(1)Mg10Zr2 cuboctahedra, edges with four equivalent Mg(4)Mg12 cuboctahedra, edges with eight equivalent Mg(3)Mg10ZrSb cuboctahedra, faces with two equivalent Mg(2)Mg10Sb2 cuboctahedra, faces with two equivalent Mg(4)Mg12 cuboctahedra, faces with two equivalent Zr(1)Mg12 cuboctahedra, faces with four equivalent Mg(1)Mg10Zr2 cuboctahedra, and faces with ten equivalent Mg(3)Mg10ZrSb cuboctahedra. In the second Mg site, Mg(2) is bonded to two equivalent Mg(4), four equivalent Mg(2), four equivalent Mg(3), and two equivalent Sb(1) atoms to form distorted MgMg10Sb2 cuboctahedra that share corners with four equivalent Zr(1)Mg12 cuboctahedra, corners with six equivalent Mg(2)Mg10Sb2 cuboctahedra, corners with eight equivalent Mg(1)Mg10Zr2 cuboctahedra, edges with two equivalent Sb(1)Mg12 cuboctahedra, edges with four equivalent Mg(2)Mg10Sb2 cuboctahedra, edges with four equivalent Mg(4)Mg12 cuboctahedra, edges with eight equivalent Mg(3)Mg10ZrSb cuboctahedra, faces with two equivalent Mg(1)Mg10Zr2 cuboctahedra, faces with two equivalent Mg(4)Mg12 cuboctahedra, faces with two equivalent Sb(1)Mg12 cuboctahedra, faces with four equivalent Mg(2)Mg10Sb2 cuboctahedra, and faces with ten equivalent Mg(3)Mg10ZrSb cuboctahedra. In the third Mg site, Mg(3) is bonded to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(4), four equivalent Mg(3), one Zr(1), and one Sb(1) atom to form distorted MgMg10ZrSb cuboctahedra that share corners with four equivalent Mg(4)Mg12 cuboctahedra, corners with fourteen equivalent Mg(3)Mg10ZrSb cuboctahedra, edges with two equivalent Mg(4)Mg12 cuboctahedra, edges with two equivalent Zr(1)Mg12 cuboctahedra, edges with two equivalent Sb(1)Mg12 cuboctahedra, edges with four equivalent Mg(2)Mg10Sb2 cuboctahedra, edges with four equivalent Mg(1)Mg10Zr2 cuboctahedra, edges with four equivalent Mg(3)Mg10ZrSb cuboctahedra,  a faceface with one Zr(1)Mg12 cuboctahedra,  a faceface with one Sb(1)Mg12 cuboctahedra, faces with two equivalent Mg(4)Mg12 cuboctahedra, faces with five equivalent Mg(2)Mg10Sb2 cuboctahedra, faces with five equivalent Mg(1)Mg10Zr2 cuboctahedra, and faces with six equivalent Mg(3)Mg10ZrSb cuboctahedra. In the fourth Mg site, Mg(4) is bonded to three equivalent Mg(1), three equivalent Mg(2), and six equivalent Mg(3) atoms to form MgMg12 cuboctahedra that share corners with six equivalent Mg(4)Mg12 cuboctahedra, corners with twelve equivalent Mg(3)Mg10ZrSb cuboctahedra, edges with six equivalent Mg(2)Mg10Sb2 cuboctahedra, edges with six equivalent Mg(1)Mg10Zr2 cuboctahedra, edges with six equivalent Mg(3)Mg10ZrSb cuboctahedra, faces with two equivalent Mg(4)Mg12 cuboctahedra, faces with three equivalent Mg(2)Mg10Sb2 cuboctahedra, faces with three equivalent Mg(1)Mg10Zr2 cuboctahedra, faces with three equivalent Zr(1)Mg12 cuboctahedra, faces with three equivalent Sb(1)Mg12 cuboctahedra, and faces with six equivalent Mg(3)Mg10ZrSb cuboctahedra. Zr(1) is bonded to six equivalent Mg(1) and six equivalent Mg(3) atoms to form ZrMg12 cuboctahedra that share corners with six equivalent Zr(1)Mg12 cuboctahedra, corners with twelve equivalent Mg(2)Mg10Sb2 cuboctahedra, edges with six equivalent Mg(1)Mg10Zr2 cuboctahedra, edges with twelve equivalent Mg(3)Mg10ZrSb cuboctahedra, faces with two equivalent Sb(1)Mg12 cuboctahedra, faces with six equivalent Mg(1)Mg10Zr2 cuboctahedra, faces with six equivalent Mg(3)Mg10ZrSb cuboctahedra, and faces with six equivalent Mg(4)Mg12 cuboctahedra. Sb(1) is bonded to six equivalent Mg(2) and six equivalent Mg(3) atoms to form SbMg12 cuboctahedra that share corners with six equivalent Sb(1)Mg12 cuboctahedra, corners with twelve equivalent Mg(1)Mg10Zr2 cuboctahedra, edges with six equivalent Mg(2)Mg10Sb2 cuboctahedra, edges with twelve equivalent Mg(3)Mg10ZrSb cuboctahedra, faces with two equivalent Zr(1)Mg12 cuboctahedra, faces with six equivalent Mg(2)Mg10Sb2 cuboctahedra, faces with six equivalent Mg(3)Mg10ZrSb cuboctahedra, and faces with six equivalent Mg(4)Mg12 cuboctahedra.
Mg14ZrSb crystallizes in the hexagonal P-6m2 space group. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Mg(4), four equivalent Mg(1), four equivalent Mg(3), and two equivalent Zr(1) atoms to form MgMg10Zr2 cuboctahedra that share corners with four equivalent Sb(1)Mg12 cuboctahedra, corners with six equivalent Mg(1)Mg10Zr2 cuboctahedra, corners with eight equivalent Mg(2)Mg10Sb2 cuboctahedra, edges with two equivalent Zr(1)Mg12 cuboctahedra, edges with four equivalent Mg(1)Mg10Zr2 cuboctahedra, edges with four equivalent Mg(4)Mg12 cuboctahedra, edges with eight equivalent Mg(3)Mg10ZrSb cuboctahedra, faces with two equivalent Mg(2)Mg10Sb2 cuboctahedra, faces with two equivalent Mg(4)Mg12 cuboctahedra, faces with two equivalent Zr(1)Mg12 cuboctahedra, faces with four equivalent Mg(1)Mg10Zr2 cuboctahedra, and faces with ten equivalent Mg(3)Mg10ZrSb cuboctahedra. Both Mg(1)-Mg(4) bond lengths are 3.15 Å. There are two shorter (3.14 Å) and two longer (3.24 Å) Mg(1)-Mg(1) bond lengths. All Mg(1)-Mg(3) bond lengths are 3.16 Å. Both Mg(1)-Zr(1) bond lengths are 3.19 Å. In the second Mg site, Mg(2) is bonded to two equivalent Mg(4), four equivalent Mg(2), four equivalent Mg(3), and two equivalent Sb(1) atoms to form distorted MgMg10Sb2 cuboctahedra that share corners with four equivalent Zr(1)Mg12 cuboctahedra, corners with six equivalent Mg(2)Mg10Sb2 cuboctahedra, corners with eight equivalent Mg(1)Mg10Zr2 cuboctahedra, edges with two equivalent Sb(1)Mg12 cuboctahedra, edges with four equivalent Mg(2)Mg10Sb2 cuboctahedra, edges with four equivalent Mg(4)Mg12 cuboctahedra, edges with eight equivalent Mg(3)Mg10ZrSb cuboctahedra, faces with two equivalent Mg(1)Mg10Zr2 cuboctahedra, faces with two equivalent Mg(4)Mg12 cuboctahedra, faces with two equivalent Sb(1)Mg12 cuboctahedra, faces with four equivalent Mg(2)Mg10Sb2 cuboctahedra, and faces with ten equivalent Mg(3)Mg10ZrSb cuboctahedra. Both Mg(2)-Mg(4) bond lengths are 3.22 Å. There are two shorter (3.16 Å) and two longer (3.22 Å) Mg(2)-Mg(2) bond lengths. All Mg(2)-Mg(3) bond lengths are 3.23 Å. Both Mg(2)-Sb(1) bond lengths are 3.19 Å. In the third Mg site, Mg(3) is bonded to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(4), four equivalent Mg(3), one Zr(1), and one Sb(1) atom to form distorted MgMg10ZrSb cuboctahedra that share corners with four equivalent Mg(4)Mg12 cuboctahedra, corners with fourteen equivalent Mg(3)Mg10ZrSb cuboctahedra, edges with two equivalent Mg(4)Mg12 cuboctahedra, edges with two equivalent Zr(1)Mg12 cuboctahedra, edges with two equivalent Sb(1)Mg12 cuboctahedra, edges with four equivalent Mg(2)Mg10Sb2 cuboctahedra, edges with four equivalent Mg(1)Mg10Zr2 cuboctahedra, edges with four equivalent Mg(3)Mg10ZrSb cuboctahedra,  a faceface with one Zr(1)Mg12 cuboctahedra,  a faceface with one Sb(1)Mg12 cuboctahedra, faces with two equivalent Mg(4)Mg12 cuboctahedra, faces with five equivalent Mg(2)Mg10Sb2 cuboctahedra, faces with five equivalent Mg(1)Mg10Zr2 cuboctahedra, and faces with six equivalent Mg(3)Mg10ZrSb cuboctahedra. Both Mg(3)-Mg(4) bond lengths are 3.19 Å. There are two shorter (3.12 Å) and two longer (3.26 Å) Mg(3)-Mg(3) bond lengths. The Mg(3)-Zr(1) bond length is 3.13 Å. The Mg(3)-Sb(1) bond length is 3.19 Å. In the fourth Mg site, Mg(4) is bonded to three equivalent Mg(1), three equivalent Mg(2), and six equivalent Mg(3) atoms to form MgMg12 cuboctahedra that share corners with six equivalent Mg(4)Mg12 cuboctahedra, corners with twelve equivalent Mg(3)Mg10ZrSb cuboctahedra, edges with six equivalent Mg(2)Mg10Sb2 cuboctahedra, edges with six equivalent Mg(1)Mg10Zr2 cuboctahedra, edges with six equivalent Mg(3)Mg10ZrSb cuboctahedra, faces with two equivalent Mg(4)Mg12 cuboctahedra, faces with three equivalent Mg(2)Mg10Sb2 cuboctahedra, faces with three equivalent Mg(1)Mg10Zr2 cuboctahedra, faces with three equivalent Zr(1)Mg12 cuboctahedra, faces with three equivalent Sb(1)Mg12 cuboctahedra, and faces with six equivalent Mg(3)Mg10ZrSb cuboctahedra. Zr(1) is bonded to six equivalent Mg(1) and six equivalent Mg(3) atoms to form ZrMg12 cuboctahedra that share corners with six equivalent Zr(1)Mg12 cuboctahedra, corners with twelve equivalent Mg(2)Mg10Sb2 cuboctahedra, edges with six equivalent Mg(1)Mg10Zr2 cuboctahedra, edges with twelve equivalent Mg(3)Mg10ZrSb cuboctahedra, faces with two equivalent Sb(1)Mg12 cuboctahedra, faces with six equivalent Mg(1)Mg10Zr2 cuboctahedra, faces with six equivalent Mg(3)Mg10ZrSb cuboctahedra, and faces with six equivalent Mg(4)Mg12 cuboctahedra. Sb(1) is bonded to six equivalent Mg(2) and six equivalent Mg(3) atoms to form SbMg12 cuboctahedra that share corners with six equivalent Sb(1)Mg12 cuboctahedra, corners with twelve equivalent Mg(1)Mg10Zr2 cuboctahedra, edges with six equivalent Mg(2)Mg10Sb2 cuboctahedra, edges with twelve equivalent Mg(3)Mg10ZrSb cuboctahedra, faces with two equivalent Zr(1)Mg12 cuboctahedra, faces with six equivalent Mg(2)Mg10Sb2 cuboctahedra, faces with six equivalent Mg(3)Mg10ZrSb cuboctahedra, and faces with six equivalent Mg(4)Mg12 cuboctahedra.