DOE OSTI2020
ZrCu2Zn20 crystallizes in the cubic Fd-3m space group. The structure is three-dimensional. Zr is bonded in a 4-coordinate geometry to sixteen Zn atoms. There are twelve shorter (3.03 Å) and four longer (3.04 Å) Zr–Zn bond lengths. Cu is bonded to twelve Zn atoms to form CuZn12 cuboctahedra that share corners with six equivalent CuZn12 cuboctahedra, edges with eighteen equivalent ZnZrZn10Cu cuboctahedra, and faces with six equivalent ZnZrZn10Cu cuboctahedra. There are six shorter (2.49 Å) and six longer (2.79 Å) Cu–Zn bond lengths. There are three inequivalent Zn sites. In the first Zn site, Zn is bonded in a 2-coordinate geometry to two equivalent Cu and six equivalent Zn atoms. There are two shorter (2.64 Å) and four longer (2.79 Å) Zn–Zn bond lengths. In the second Zn site, Zn is bonded to one Zr, one Cu, and ten Zn atoms to form ZnZrZn10Cu cuboctahedra that share corners with fifteen equivalent ZnZrZn10Cu cuboctahedra, edges with two equivalent ZnZrZn10Cu cuboctahedra, edges with three equivalent CuZn12 cuboctahedra, a faceface with one CuZn12 cuboctahedra, and faces with fifteen equivalent ZnZrZn10Cu cuboctahedra. There are a spread of Zn–Zn bond distances ranging from 2.55–2.96 Å. In the third Zn site, Zn is bonded in a 2-coordinate geometry to two equivalent Zr and twelve equivalent Zn atoms.