Mg14MnSn 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 Mn(1) atoms to form MgMg10Mn2 cuboctahedra that share corners with four equivalent Sn(1)Mg12 cuboctahedra, corners with six equivalent Mg(1)Mg10Mn2 cuboctahedra, edges with two equivalent Mn(1)Mg12 cuboctahedra, edges with four equivalent Mg(1)Mg10Mn2 cuboctahedra, edges with four equivalent Mg(4)Mg12 cuboctahedra, edges with eight equivalent Mg(3)Mg10MnSn cuboctahedra, faces with two equivalent Mg(4)Mg12 cuboctahedra, faces with two equivalent Mn(1)Mg12 cuboctahedra, faces with four equivalent Mg(1)Mg10Mn2 cuboctahedra, and faces with ten equivalent Mg(3)Mg10MnSn cuboctahedra. In the second Mg site, Mg(2) is bonded in a distorted linear geometry to two equivalent Mg(4), four equivalent Mg(3), and two equivalent Sn(1) atoms. 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 Mn(1), and one Sn(1) atom to form distorted MgMg10MnSn cuboctahedra that share corners with four equivalent Mg(4)Mg12 cuboctahedra, corners with fourteen equivalent Mg(3)Mg10MnSn cuboctahedra, edges with two equivalent Mg(4)Mg12 cuboctahedra, edges with two equivalent Mn(1)Mg12 cuboctahedra, edges with two equivalent Sn(1)Mg12 cuboctahedra, edges with four equivalent Mg(1)Mg10Mn2 cuboctahedra, edges with four equivalent Mg(3)Mg10MnSn cuboctahedra,  a faceface with one Mn(1)Mg12 cuboctahedra,  a faceface with one Sn(1)Mg12 cuboctahedra, faces with two equivalent Mg(4)Mg12 cuboctahedra, faces with five equivalent Mg(1)Mg10Mn2 cuboctahedra, and faces with six equivalent Mg(3)Mg10MnSn 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)Mg10MnSn cuboctahedra, edges with six equivalent Mg(1)Mg10Mn2 cuboctahedra, edges with six equivalent Mg(3)Mg10MnSn cuboctahedra, faces with two equivalent Mg(4)Mg12 cuboctahedra, faces with three equivalent Mg(1)Mg10Mn2 cuboctahedra, faces with three equivalent Mn(1)Mg12 cuboctahedra, faces with three equivalent Sn(1)Mg12 cuboctahedra, and faces with six equivalent Mg(3)Mg10MnSn cuboctahedra. Mn(1) is bonded to six equivalent Mg(1) and six equivalent Mg(3) atoms to form MnMg12 cuboctahedra that share corners with six equivalent Mn(1)Mg12 cuboctahedra, edges with six equivalent Mg(1)Mg10Mn2 cuboctahedra, edges with twelve equivalent Mg(3)Mg10MnSn cuboctahedra, faces with two equivalent Sn(1)Mg12 cuboctahedra, faces with six equivalent Mg(1)Mg10Mn2 cuboctahedra, faces with six equivalent Mg(3)Mg10MnSn cuboctahedra, and faces with six equivalent Mg(4)Mg12 cuboctahedra. Sn(1) is bonded to six equivalent Mg(2) and six equivalent Mg(3) atoms to form SnMg12 cuboctahedra that share corners with six equivalent Sn(1)Mg12 cuboctahedra, corners with twelve equivalent Mg(1)Mg10Mn2 cuboctahedra, edges with twelve equivalent Mg(3)Mg10MnSn cuboctahedra, faces with two equivalent Mn(1)Mg12 cuboctahedra, faces with six equivalent Mg(3)Mg10MnSn cuboctahedra, and faces with six equivalent Mg(4)Mg12 cuboctahedra.
Mg14MnSn 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 Mn(1) atoms to form MgMg10Mn2 cuboctahedra that share corners with four equivalent Sn(1)Mg12 cuboctahedra, corners with six equivalent Mg(1)Mg10Mn2 cuboctahedra, edges with two equivalent Mn(1)Mg12 cuboctahedra, edges with four equivalent Mg(1)Mg10Mn2 cuboctahedra, edges with four equivalent Mg(4)Mg12 cuboctahedra, edges with eight equivalent Mg(3)Mg10MnSn cuboctahedra, faces with two equivalent Mg(4)Mg12 cuboctahedra, faces with two equivalent Mn(1)Mg12 cuboctahedra, faces with four equivalent Mg(1)Mg10Mn2 cuboctahedra, and faces with ten equivalent Mg(3)Mg10MnSn cuboctahedra. Both Mg(1)-Mg(4) bond lengths are 3.15 Å. All Mg(1)-Mg(1) bond lengths are 3.14 Å. All Mg(1)-Mg(3) bond lengths are 3.11 Å. Both Mg(1)-Mn(1) bond lengths are 3.14 Å. In the second Mg site, Mg(2) is bonded in a distorted linear geometry to two equivalent Mg(4), four equivalent Mg(3), and two equivalent Sn(1) atoms. Both Mg(2)-Mg(4) bond lengths are 3.18 Å. All Mg(2)-Mg(3) bond lengths are 3.24 Å. Both Mg(2)-Sn(1) bond lengths are 3.14 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 Mn(1), and one Sn(1) atom to form distorted MgMg10MnSn cuboctahedra that share corners with four equivalent Mg(4)Mg12 cuboctahedra, corners with fourteen equivalent Mg(3)Mg10MnSn cuboctahedra, edges with two equivalent Mg(4)Mg12 cuboctahedra, edges with two equivalent Mn(1)Mg12 cuboctahedra, edges with two equivalent Sn(1)Mg12 cuboctahedra, edges with four equivalent Mg(1)Mg10Mn2 cuboctahedra, edges with four equivalent Mg(3)Mg10MnSn cuboctahedra,  a faceface with one Mn(1)Mg12 cuboctahedra,  a faceface with one Sn(1)Mg12 cuboctahedra, faces with two equivalent Mg(4)Mg12 cuboctahedra, faces with five equivalent Mg(1)Mg10Mn2 cuboctahedra, and faces with six equivalent Mg(3)Mg10MnSn cuboctahedra. Both Mg(3)-Mg(4) bond lengths are 3.14 Å. There are two shorter (3.09 Å) and two longer (3.19 Å) Mg(3)-Mg(3) bond lengths. The Mg(3)-Mn(1) bond length is 3.08 Å. The Mg(3)-Sn(1) bond length is 3.22 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)Mg10MnSn cuboctahedra, edges with six equivalent Mg(1)Mg10Mn2 cuboctahedra, edges with six equivalent Mg(3)Mg10MnSn cuboctahedra, faces with two equivalent Mg(4)Mg12 cuboctahedra, faces with three equivalent Mg(1)Mg10Mn2 cuboctahedra, faces with three equivalent Mn(1)Mg12 cuboctahedra, faces with three equivalent Sn(1)Mg12 cuboctahedra, and faces with six equivalent Mg(3)Mg10MnSn cuboctahedra. Mn(1) is bonded to six equivalent Mg(1) and six equivalent Mg(3) atoms to form MnMg12 cuboctahedra that share corners with six equivalent Mn(1)Mg12 cuboctahedra, edges with six equivalent Mg(1)Mg10Mn2 cuboctahedra, edges with twelve equivalent Mg(3)Mg10MnSn cuboctahedra, faces with two equivalent Sn(1)Mg12 cuboctahedra, faces with six equivalent Mg(1)Mg10Mn2 cuboctahedra, faces with six equivalent Mg(3)Mg10MnSn cuboctahedra, and faces with six equivalent Mg(4)Mg12 cuboctahedra. Sn(1) is bonded to six equivalent Mg(2) and six equivalent Mg(3) atoms to form SnMg12 cuboctahedra that share corners with six equivalent Sn(1)Mg12 cuboctahedra, corners with twelve equivalent Mg(1)Mg10Mn2 cuboctahedra, edges with twelve equivalent Mg(3)Mg10MnSn cuboctahedra, faces with two equivalent Mn(1)Mg12 cuboctahedra, faces with six equivalent Mg(3)Mg10MnSn cuboctahedra, and faces with six equivalent Mg(4)Mg12 cuboctahedra.