MgAl2 crystallizes in the tetragonal I4_1/amd space group. Mg(1) is bonded to two equivalent Mg(1), four equivalent Al(1), and six equivalent Al(2) atoms to form distorted MgMg2Al10 cuboctahedra that share corners with four equivalent Al(1)Mg4Al8 cuboctahedra, corners with eight equivalent Mg(1)Mg2Al10 cuboctahedra, edges with four equivalent Mg(1)Mg2Al10 cuboctahedra, edges with twelve equivalent Al(1)Mg4Al8 cuboctahedra, faces with five equivalent Al(1)Mg4Al8 cuboctahedra, and faces with seven equivalent Mg(1)Mg2Al10 cuboctahedra. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to four equivalent Mg(1), four equivalent Al(1), and four equivalent Al(2) atoms to form AlMg4Al8 cuboctahedra that share corners with four equivalent Mg(1)Mg2Al10 cuboctahedra, corners with four equivalent Al(1)Mg4Al8 cuboctahedra, edges with twelve equivalent Mg(1)Mg2Al10 cuboctahedra, faces with five equivalent Mg(1)Mg2Al10 cuboctahedra, and faces with eight equivalent Al(1)Mg4Al8 cuboctahedra. In the second Al site, Al(2) is bonded in a 12-coordinate geometry to six equivalent Mg(1), two equivalent Al(2), and four equivalent Al(1) atoms.
MgAl2 crystallizes in the tetragonal I4_1/amd space group. Mg(1) is bonded to two equivalent Mg(1), four equivalent Al(1), and six equivalent Al(2) atoms to form distorted MgMg2Al10 cuboctahedra that share corners with four equivalent Al(1)Mg4Al8 cuboctahedra, corners with eight equivalent Mg(1)Mg2Al10 cuboctahedra, edges with four equivalent Mg(1)Mg2Al10 cuboctahedra, edges with twelve equivalent Al(1)Mg4Al8 cuboctahedra, faces with five equivalent Al(1)Mg4Al8 cuboctahedra, and faces with seven equivalent Mg(1)Mg2Al10 cuboctahedra. Both Mg(1)-Mg(1) bond lengths are 3.07 Å. There are two shorter (2.96 Å) and two longer (2.97 Å) Mg(1)-Al(1) bond lengths. There are four shorter (2.91 Å) and two longer (3.09 Å) Mg(1)-Al(2) bond lengths. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to four equivalent Mg(1), four equivalent Al(1), and four equivalent Al(2) atoms to form AlMg4Al8 cuboctahedra that share corners with four equivalent Mg(1)Mg2Al10 cuboctahedra, corners with four equivalent Al(1)Mg4Al8 cuboctahedra, edges with twelve equivalent Mg(1)Mg2Al10 cuboctahedra, faces with five equivalent Mg(1)Mg2Al10 cuboctahedra, and faces with eight equivalent Al(1)Mg4Al8 cuboctahedra. All Al(1)-Al(1) bond lengths are 2.91 Å. There are two shorter (2.94 Å) and two longer (2.95 Å) Al(1)-Al(2) bond lengths. In the second Al site, Al(2) is bonded in a 12-coordinate geometry to six equivalent Mg(1), two equivalent Al(2), and four equivalent Al(1) atoms. Both Al(2)-Al(2) bond lengths are 3.11 Å.