Sm(CuAl2)4 crystallizes in the monoclinic C2/m space group. Sm(1) is bonded in a 20-coordinate geometry to two equivalent Cu(2), two equivalent Cu(3), four equivalent Cu(1), four equivalent Al(1), and eight equivalent Al(2) atoms. There are three inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to two equivalent Sm(1), two equivalent Cu(1), four equivalent Al(1), and four equivalent Al(2) atoms to form a mixture of distorted corner, face, and edge-sharing CuSm2Al8Cu2 cuboctahedra. In the second Cu site, Cu(2) is bonded to two equivalent Sm(1), two equivalent Cu(3), four equivalent Al(1), and four equivalent Al(2) atoms to form a mixture of distorted corner, face, and edge-sharing CuSm2Al8Cu2 cuboctahedra. In the third Cu site, Cu(3) is bonded to two equivalent Sm(1), two equivalent Cu(2), four equivalent Al(1), and four equivalent Al(2) atoms to form a mixture of distorted corner, face, and edge-sharing CuSm2Al8Cu2 cuboctahedra. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded in a 10-coordinate geometry to one Sm(1), one Cu(2), one Cu(3), two equivalent Cu(1), one Al(1), and four equivalent Al(2) atoms. In the second Al site, Al(2) is bonded in a 12-coordinate geometry to two equivalent Sm(1), one Cu(2), one Cu(3), two equivalent Cu(1), two equivalent Al(2), and four equivalent Al(1) atoms.
Sm(CuAl2)4 crystallizes in the monoclinic C2/m space group. Sm(1) is bonded in a 20-coordinate geometry to two equivalent Cu(2), two equivalent Cu(3), four equivalent Cu(1), four equivalent Al(1), and eight equivalent Al(2) atoms. Both Sm(1)-Cu(2) bond lengths are 3.35 Å. Both Sm(1)-Cu(3) bond lengths are 3.35 Å. All Sm(1)-Cu(1) bond lengths are 3.35 Å. All Sm(1)-Al(1) bond lengths are 3.06 Å. There are four shorter (3.20 Å) and four longer (3.21 Å) Sm(1)-Al(2) bond lengths. There are three inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to two equivalent Sm(1), two equivalent Cu(1), four equivalent Al(1), and four equivalent Al(2) atoms to form a mixture of distorted corner, face, and edge-sharing CuSm2Al8Cu2 cuboctahedra. Both Cu(1)-Cu(1) bond lengths are 2.56 Å. All Cu(1)-Al(1) bond lengths are 2.68 Å. All Cu(1)-Al(2) bond lengths are 2.55 Å. In the second Cu site, Cu(2) is bonded to two equivalent Sm(1), two equivalent Cu(3), four equivalent Al(1), and four equivalent Al(2) atoms to form a mixture of distorted corner, face, and edge-sharing CuSm2Al8Cu2 cuboctahedra. Both Cu(2)-Cu(3) bond lengths are 2.56 Å. All Cu(2)-Al(1) bond lengths are 2.68 Å. All Cu(2)-Al(2) bond lengths are 2.55 Å. In the third Cu site, Cu(3) is bonded to two equivalent Sm(1), two equivalent Cu(2), four equivalent Al(1), and four equivalent Al(2) atoms to form a mixture of distorted corner, face, and edge-sharing CuSm2Al8Cu2 cuboctahedra. All Cu(3)-Al(1) bond lengths are 2.68 Å. All Cu(3)-Al(2) bond lengths are 2.55 Å. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded in a 10-coordinate geometry to one Sm(1), one Cu(2), one Cu(3), two equivalent Cu(1), one Al(1), and four equivalent Al(2) atoms. The Al(1)-Al(1) bond length is 2.65 Å. There are two shorter (2.78 Å) and two longer (2.79 Å) Al(1)-Al(2) bond lengths. In the second Al site, Al(2) is bonded in a 12-coordinate geometry to two equivalent Sm(1), one Cu(2), one Cu(3), two equivalent Cu(1), two equivalent Al(2), and four equivalent Al(1) atoms. Both Al(2)-Al(2) bond lengths are 2.73 Å.