LiMg2 is Molybdenite structured and crystallizes in the hexagonal P6_3/mmc space group. Li(1) is bonded to six equivalent Mg(1) atoms to form distorted LiMg6 cuboctahedra that share corners with twenty-four equivalent Mg(1)Li3Mg9 cuboctahedra, edges with six equivalent Li(1)Mg6 cuboctahedra, edges with twelve equivalent Mg(1)Li3Mg9 cuboctahedra, and faces with two equivalent Mg(1)Li3Mg9 cuboctahedra. Mg(1) is bonded to three equivalent Li(1) and nine equivalent Mg(1) atoms to form distorted MgLi3Mg9 cuboctahedra that share corners with twelve equivalent Li(1)Mg6 cuboctahedra, corners with twelve equivalent Mg(1)Li3Mg9 cuboctahedra, edges with six equivalent Li(1)Mg6 cuboctahedra, edges with twelve equivalent Mg(1)Li3Mg9 cuboctahedra,  a faceface with one Li(1)Mg6 cuboctahedra, and faces with thirteen equivalent Mg(1)Li3Mg9 cuboctahedra.
LiMg2 is Molybdenite structured and crystallizes in the hexagonal P6_3/mmc space group. Li(1) is bonded to six equivalent Mg(1) atoms to form distorted LiMg6 cuboctahedra that share corners with twenty-four equivalent Mg(1)Li3Mg9 cuboctahedra, edges with six equivalent Li(1)Mg6 cuboctahedra, edges with twelve equivalent Mg(1)Li3Mg9 cuboctahedra, and faces with two equivalent Mg(1)Li3Mg9 cuboctahedra. All Li(1)-Mg(1) bond lengths are 3.06 Å. Mg(1) is bonded to three equivalent Li(1) and nine equivalent Mg(1) atoms to form distorted MgLi3Mg9 cuboctahedra that share corners with twelve equivalent Li(1)Mg6 cuboctahedra, corners with twelve equivalent Mg(1)Li3Mg9 cuboctahedra, edges with six equivalent Li(1)Mg6 cuboctahedra, edges with twelve equivalent Mg(1)Li3Mg9 cuboctahedra,  a faceface with one Li(1)Mg6 cuboctahedra, and faces with thirteen equivalent Mg(1)Li3Mg9 cuboctahedra. There are three shorter (3.15 Å) and six longer (3.16 Å) Mg(1)-Mg(1) bond lengths.