Li5Mg crystallizes in the hexagonal P-62m space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to four equivalent Li(2), six equivalent Li(1), and two equivalent Mg(1) atoms to form LiLi10Mg2 cuboctahedra that share corners with eighteen equivalent Li(1)Li10Mg2 cuboctahedra, edges with four equivalent Mg(1)Li12 cuboctahedra, edges with six equivalent Li(1)Li10Mg2 cuboctahedra, edges with eight equivalent Li(2)Li9Mg3 cuboctahedra, faces with four equivalent Mg(1)Li12 cuboctahedra, faces with eight equivalent Li(1)Li10Mg2 cuboctahedra, and faces with eight equivalent Li(2)Li9Mg3 cuboctahedra. In the second Li site, Li(2) is bonded to three equivalent Li(2), six equivalent Li(1), and three equivalent Mg(1) atoms to form distorted LiLi9Mg3 cuboctahedra that share corners with nine equivalent Li(2)Li9Mg3 cuboctahedra, corners with nine equivalent Mg(1)Li12 cuboctahedra, edges with six equivalent Li(2)Li9Mg3 cuboctahedra, edges with twelve equivalent Li(1)Li10Mg2 cuboctahedra, faces with three equivalent Mg(1)Li12 cuboctahedra, faces with five equivalent Li(2)Li9Mg3 cuboctahedra, and faces with twelve equivalent Li(1)Li10Mg2 cuboctahedra. Mg(1) is bonded to six equivalent Li(1) and six equivalent Li(2) atoms to form MgLi12 cuboctahedra that share corners with eighteen equivalent Li(2)Li9Mg3 cuboctahedra, edges with six equivalent Mg(1)Li12 cuboctahedra, edges with twelve equivalent Li(1)Li10Mg2 cuboctahedra, faces with two equivalent Mg(1)Li12 cuboctahedra, faces with six equivalent Li(2)Li9Mg3 cuboctahedra, and faces with twelve equivalent Li(1)Li10Mg2 cuboctahedra.
Li5Mg crystallizes in the hexagonal P-62m space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to four equivalent Li(2), six equivalent Li(1), and two equivalent Mg(1) atoms to form LiLi10Mg2 cuboctahedra that share corners with eighteen equivalent Li(1)Li10Mg2 cuboctahedra, edges with four equivalent Mg(1)Li12 cuboctahedra, edges with six equivalent Li(1)Li10Mg2 cuboctahedra, edges with eight equivalent Li(2)Li9Mg3 cuboctahedra, faces with four equivalent Mg(1)Li12 cuboctahedra, faces with eight equivalent Li(1)Li10Mg2 cuboctahedra, and faces with eight equivalent Li(2)Li9Mg3 cuboctahedra. All Li(1)-Li(2) bond lengths are 3.08 Å. There are two shorter (3.04 Å) and four longer (3.05 Å) Li(1)-Li(1) bond lengths. Both Li(1)-Mg(1) bond lengths are 3.07 Å. In the second Li site, Li(2) is bonded to three equivalent Li(2), six equivalent Li(1), and three equivalent Mg(1) atoms to form distorted LiLi9Mg3 cuboctahedra that share corners with nine equivalent Li(2)Li9Mg3 cuboctahedra, corners with nine equivalent Mg(1)Li12 cuboctahedra, edges with six equivalent Li(2)Li9Mg3 cuboctahedra, edges with twelve equivalent Li(1)Li10Mg2 cuboctahedra, faces with three equivalent Mg(1)Li12 cuboctahedra, faces with five equivalent Li(2)Li9Mg3 cuboctahedra, and faces with twelve equivalent Li(1)Li10Mg2 cuboctahedra. All Li(2)-Li(2) bond lengths are 3.05 Å. All Li(2)-Mg(1) bond lengths are 3.05 Å. Mg(1) is bonded to six equivalent Li(1) and six equivalent Li(2) atoms to form MgLi12 cuboctahedra that share corners with eighteen equivalent Li(2)Li9Mg3 cuboctahedra, edges with six equivalent Mg(1)Li12 cuboctahedra, edges with twelve equivalent Li(1)Li10Mg2 cuboctahedra, faces with two equivalent Mg(1)Li12 cuboctahedra, faces with six equivalent Li(2)Li9Mg3 cuboctahedra, and faces with twelve equivalent Li(1)Li10Mg2 cuboctahedra.