Mg2La crystallizes in the monoclinic C2/c space group. Mg(1) is bonded to seven equivalent Mg(1) and five equivalent La(1) atoms to form distorted MgLa5Mg7 cuboctahedra that share corners with six equivalent La(1)La2Mg10 cuboctahedra, corners with twelve equivalent Mg(1)La5Mg7 cuboctahedra, edges with four equivalent La(1)La2Mg10 cuboctahedra, edges with fourteen equivalent Mg(1)La5Mg7 cuboctahedra, faces with eight equivalent La(1)La2Mg10 cuboctahedra, and faces with twelve equivalent Mg(1)La5Mg7 cuboctahedra. La(1) is bonded to ten equivalent Mg(1) and two equivalent La(1) atoms to form LaLa2Mg10 cuboctahedra that share corners with six equivalent La(1)La2Mg10 cuboctahedra, corners with twelve equivalent Mg(1)La5Mg7 cuboctahedra, edges with eight equivalent Mg(1)La5Mg7 cuboctahedra, edges with ten equivalent La(1)La2Mg10 cuboctahedra, faces with four equivalent La(1)La2Mg10 cuboctahedra, and faces with sixteen equivalent Mg(1)La5Mg7 cuboctahedra.
Mg2La crystallizes in the monoclinic C2/c space group. Mg(1) is bonded to seven equivalent Mg(1) and five equivalent La(1) atoms to form distorted MgLa5Mg7 cuboctahedra that share corners with six equivalent La(1)La2Mg10 cuboctahedra, corners with twelve equivalent Mg(1)La5Mg7 cuboctahedra, edges with four equivalent La(1)La2Mg10 cuboctahedra, edges with fourteen equivalent Mg(1)La5Mg7 cuboctahedra, faces with eight equivalent La(1)La2Mg10 cuboctahedra, and faces with twelve equivalent Mg(1)La5Mg7 cuboctahedra. There are a spread of Mg(1)-Mg(1) bond distances ranging from 3.37-3.50 Å. There are a spread of Mg(1)-La(1) bond distances ranging from 3.36-3.53 Å. La(1) is bonded to ten equivalent Mg(1) and two equivalent La(1) atoms to form LaLa2Mg10 cuboctahedra that share corners with six equivalent La(1)La2Mg10 cuboctahedra, corners with twelve equivalent Mg(1)La5Mg7 cuboctahedra, edges with eight equivalent Mg(1)La5Mg7 cuboctahedra, edges with ten equivalent La(1)La2Mg10 cuboctahedra, faces with four equivalent La(1)La2Mg10 cuboctahedra, and faces with sixteen equivalent Mg(1)La5Mg7 cuboctahedra. Both La(1)-La(1) bond lengths are 3.38 Å.