Al3Dy crystallizes in the trigonal R-3m space group. There are two inequivalent Dy sites. In the first Dy site, Dy(1) is bonded to six equivalent Al(1) and six equivalent Al(2) atoms to form DyAl12 cuboctahedra that share corners with six equivalent Dy(1)Al12 cuboctahedra, edges with six equivalent Al(1)Dy4Al8 cuboctahedra, faces with six equivalent Al(1)Dy4Al8 cuboctahedra, and faces with eight equivalent Dy(2)Al12 cuboctahedra. In the second Dy site, Dy(2) is bonded to three equivalent Al(1) and nine equivalent Al(2) atoms to form distorted DyAl12 cuboctahedra that share corners with six equivalent Al(1)Dy4Al8 cuboctahedra, corners with nine equivalent Dy(2)Al12 cuboctahedra, edges with six equivalent Al(1)Dy4Al8 cuboctahedra, faces with three equivalent Dy(2)Al12 cuboctahedra, faces with three equivalent Al(1)Dy4Al8 cuboctahedra, and faces with four equivalent Dy(1)Al12 cuboctahedra. There are two inequivalent Al sites. In the first Al site, Al(2) is bonded in a 10-coordinate geometry to one Dy(1), three equivalent Dy(2), two equivalent Al(1), and four equivalent Al(2) atoms. In the second Al site, Al(1) is bonded to two equivalent Dy(1), two equivalent Dy(2), four equivalent Al(1), and four equivalent Al(2) atoms to form distorted AlDy4Al8 cuboctahedra that share corners with four equivalent Dy(2)Al12 cuboctahedra, corners with six equivalent Al(1)Dy4Al8 cuboctahedra, edges with two equivalent Dy(1)Al12 cuboctahedra, edges with four equivalent Dy(2)Al12 cuboctahedra, edges with four equivalent Al(1)Dy4Al8 cuboctahedra, faces with two equivalent Dy(1)Al12 cuboctahedra, faces with two equivalent Dy(2)Al12 cuboctahedra, and faces with four equivalent Al(1)Dy4Al8 cuboctahedra.
Al3Dy crystallizes in the trigonal R-3m space group. There are two inequivalent Dy sites. In the first Dy site, Dy(1) is bonded to six equivalent Al(1) and six equivalent Al(2) atoms to form DyAl12 cuboctahedra that share corners with six equivalent Dy(1)Al12 cuboctahedra, edges with six equivalent Al(1)Dy4Al8 cuboctahedra, faces with six equivalent Al(1)Dy4Al8 cuboctahedra, and faces with eight equivalent Dy(2)Al12 cuboctahedra. All Dy(1)-Al(1) bond lengths are 3.08 Å. All Dy(1)-Al(2) bond lengths are 3.06 Å. In the second Dy site, Dy(2) is bonded to three equivalent Al(1) and nine equivalent Al(2) atoms to form distorted DyAl12 cuboctahedra that share corners with six equivalent Al(1)Dy4Al8 cuboctahedra, corners with nine equivalent Dy(2)Al12 cuboctahedra, edges with six equivalent Al(1)Dy4Al8 cuboctahedra, faces with three equivalent Dy(2)Al12 cuboctahedra, faces with three equivalent Al(1)Dy4Al8 cuboctahedra, and faces with four equivalent Dy(1)Al12 cuboctahedra. All Dy(2)-Al(1) bond lengths are 3.01 Å. There are three shorter (3.01 Å) and six longer (3.09 Å) Dy(2)-Al(2) bond lengths. There are two inequivalent Al sites. In the first Al site, Al(2) is bonded in a 10-coordinate geometry to one Dy(1), three equivalent Dy(2), two equivalent Al(1), and four equivalent Al(2) atoms. Both Al(2)-Al(1) bond lengths are 2.86 Å. There are two shorter (2.70 Å) and two longer (2.83 Å) Al(2)-Al(2) bond lengths. In the second Al site, Al(1) is bonded to two equivalent Dy(1), two equivalent Dy(2), four equivalent Al(1), and four equivalent Al(2) atoms to form distorted AlDy4Al8 cuboctahedra that share corners with four equivalent Dy(2)Al12 cuboctahedra, corners with six equivalent Al(1)Dy4Al8 cuboctahedra, edges with two equivalent Dy(1)Al12 cuboctahedra, edges with four equivalent Dy(2)Al12 cuboctahedra, edges with four equivalent Al(1)Dy4Al8 cuboctahedra, faces with two equivalent Dy(1)Al12 cuboctahedra, faces with two equivalent Dy(2)Al12 cuboctahedra, and faces with four equivalent Al(1)Dy4Al8 cuboctahedra. All Al(1)-Al(1) bond lengths are 3.08 Å.