MgLa2Al3 crystallizes in the trigonal R-3m space group. Mg(1) is bonded to six equivalent La(1) and six equivalent Al(1) atoms to form distorted MgLa6Al6 cuboctahedra that share corners with six equivalent Mg(1)La6Al6 cuboctahedra, corners with twelve equivalent Al(1)La6Mg2Al4 cuboctahedra, edges with six equivalent Mg(1)La6Al6 cuboctahedra, and faces with eighteen equivalent Al(1)La6Mg2Al4 cuboctahedra. La(1) is bonded in a 16-coordinate geometry to three equivalent Mg(1), four equivalent La(1), and nine equivalent Al(1) atoms. Al(1) is bonded to two equivalent Mg(1), six equivalent La(1), and four equivalent Al(1) atoms to form AlLa6Mg2Al4 cuboctahedra that share corners with four equivalent Mg(1)La6Al6 cuboctahedra, corners with fourteen equivalent Al(1)La6Mg2Al4 cuboctahedra, edges with six equivalent Al(1)La6Mg2Al4 cuboctahedra, faces with six equivalent Mg(1)La6Al6 cuboctahedra, and faces with twelve equivalent Al(1)La6Mg2Al4 cuboctahedra.
MgLa2Al3 crystallizes in the trigonal R-3m space group. Mg(1) is bonded to six equivalent La(1) and six equivalent Al(1) atoms to form distorted MgLa6Al6 cuboctahedra that share corners with six equivalent Mg(1)La6Al6 cuboctahedra, corners with twelve equivalent Al(1)La6Mg2Al4 cuboctahedra, edges with six equivalent Mg(1)La6Al6 cuboctahedra, and faces with eighteen equivalent Al(1)La6Mg2Al4 cuboctahedra. All Mg(1)-La(1) bond lengths are 3.46 Å. All Mg(1)-Al(1) bond lengths are 2.90 Å. La(1) is bonded in a 16-coordinate geometry to three equivalent Mg(1), four equivalent La(1), and nine equivalent Al(1) atoms. There is one shorter (3.35 Å) and three longer (3.65 Å) La(1)-La(1) bond lengths. There are six shorter (3.38 Å) and three longer (3.47 Å) La(1)-Al(1) bond lengths. Al(1) is bonded to two equivalent Mg(1), six equivalent La(1), and four equivalent Al(1) atoms to form AlLa6Mg2Al4 cuboctahedra that share corners with four equivalent Mg(1)La6Al6 cuboctahedra, corners with fourteen equivalent Al(1)La6Mg2Al4 cuboctahedra, edges with six equivalent Al(1)La6Mg2Al4 cuboctahedra, faces with six equivalent Mg(1)La6Al6 cuboctahedra, and faces with twelve equivalent Al(1)La6Mg2Al4 cuboctahedra. All Al(1)-Al(1) bond lengths are 2.94 Å.