MgLa crystallizes in the monoclinic C2 space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent La(2) and six equivalent La(1) atoms to form distorted MgLa8 cuboctahedra that share corners with two equivalent Mg(1)La8 cuboctahedra, corners with four equivalent La(2)La4Mg8 cuboctahedra, corners with ten equivalent La(1)La5Mg7 cuboctahedra, edges with two equivalent La(1)La5Mg7 cuboctahedra, edges with four equivalent La(2)La4Mg8 cuboctahedra, edges with six equivalent Mg(1)La8 cuboctahedra, and faces with four equivalent La(1)La5Mg7 cuboctahedra. In the second Mg site, Mg(2) is bonded in a 7-coordinate geometry to three equivalent La(2) and four equivalent La(1) atoms. There are two inequivalent La sites. In the first La site, La(1) is bonded to three equivalent Mg(1), four equivalent Mg(2), two equivalent La(2), and three equivalent La(1) atoms to form distorted LaLa5Mg7 cuboctahedra that share corners with five equivalent Mg(1)La8 cuboctahedra, corners with twelve equivalent La(1)La5Mg7 cuboctahedra,  an edgeedge with one Mg(1)La8 cuboctahedra, edges with four equivalent La(2)La4Mg8 cuboctahedra, edges with six equivalent La(1)La5Mg7 cuboctahedra, faces with two equivalent Mg(1)La8 cuboctahedra, faces with four equivalent La(2)La4Mg8 cuboctahedra, and faces with four equivalent La(1)La5Mg7 cuboctahedra. In the second La site, La(2) is bonded to two equivalent Mg(1), six equivalent Mg(2), and four equivalent La(1) atoms to form distorted LaLa4Mg8 cuboctahedra that share corners with four equivalent Mg(1)La8 cuboctahedra, corners with six equivalent La(2)La4Mg8 cuboctahedra, edges with four equivalent Mg(1)La8 cuboctahedra, edges with six equivalent La(2)La4Mg8 cuboctahedra, edges with eight equivalent La(1)La5Mg7 cuboctahedra, and faces with eight equivalent La(1)La5Mg7 cuboctahedra.
MgLa crystallizes in the monoclinic C2 space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent La(2) and six equivalent La(1) atoms to form distorted MgLa8 cuboctahedra that share corners with two equivalent Mg(1)La8 cuboctahedra, corners with four equivalent La(2)La4Mg8 cuboctahedra, corners with ten equivalent La(1)La5Mg7 cuboctahedra, edges with two equivalent La(1)La5Mg7 cuboctahedra, edges with four equivalent La(2)La4Mg8 cuboctahedra, edges with six equivalent Mg(1)La8 cuboctahedra, and faces with four equivalent La(1)La5Mg7 cuboctahedra. Both Mg(1)-La(2) bond lengths are 3.50 Å. There are a spread of Mg(1)-La(1) bond distances ranging from 3.45-3.57 Å. In the second Mg site, Mg(2) is bonded in a 7-coordinate geometry to three equivalent La(2) and four equivalent La(1) atoms. There are a spread of Mg(2)-La(2) bond distances ranging from 3.44-3.60 Å. There are a spread of Mg(2)-La(1) bond distances ranging from 3.44-3.58 Å. There are two inequivalent La sites. In the first La site, La(1) is bonded to three equivalent Mg(1), four equivalent Mg(2), two equivalent La(2), and three equivalent La(1) atoms to form distorted LaLa5Mg7 cuboctahedra that share corners with five equivalent Mg(1)La8 cuboctahedra, corners with twelve equivalent La(1)La5Mg7 cuboctahedra,  an edgeedge with one Mg(1)La8 cuboctahedra, edges with four equivalent La(2)La4Mg8 cuboctahedra, edges with six equivalent La(1)La5Mg7 cuboctahedra, faces with two equivalent Mg(1)La8 cuboctahedra, faces with four equivalent La(2)La4Mg8 cuboctahedra, and faces with four equivalent La(1)La5Mg7 cuboctahedra. Both La(1)-La(2) bond lengths are 3.55 Å. There is one shorter (3.39 Å) and two longer (3.57 Å) La(1)-La(1) bond lengths. In the second La site, La(2) is bonded to two equivalent Mg(1), six equivalent Mg(2), and four equivalent La(1) atoms to form distorted LaLa4Mg8 cuboctahedra that share corners with four equivalent Mg(1)La8 cuboctahedra, corners with six equivalent La(2)La4Mg8 cuboctahedra, edges with four equivalent Mg(1)La8 cuboctahedra, edges with six equivalent La(2)La4Mg8 cuboctahedra, edges with eight equivalent La(1)La5Mg7 cuboctahedra, and faces with eight equivalent La(1)La5Mg7 cuboctahedra.