DOE OSTI2020
Sc6Pd7Al16 crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. Sc is bonded in a 4-coordinate geometry to four equivalent Pd and eight Al atoms. All Sc–Pd bond lengths are 3.20 Å. There are four shorter (2.93 Å) and four longer (3.16 Å) Sc–Al bond lengths. There are two inequivalent Pd sites. In the first Pd site, Pd is bonded to four equivalent Sc and eight Al atoms to form distorted PdSc4Al8 cuboctahedra that share corners with four equivalent PdSc4Al8 cuboctahedra, corners with eight equivalent AlSc3Pd4 tetrahedra, edges with four equivalent AlSc3Pd4 tetrahedra, and faces with eight equivalent PdSc4Al8 cuboctahedra. There are four shorter (2.55 Å) and four longer (2.73 Å) Pd–Al bond lengths. In the second Pd site, Pd is bonded in a body-centered cubic geometry to eight equivalent Al atoms. All Pd–Al bond lengths are 2.60 Å. There are two inequivalent Al sites. In the first Al site, Al is bonded in a 3-coordinate geometry to three equivalent Sc and three equivalent Pd atoms. In the second Al site, Al is bonded to three equivalent Sc and four Pd atoms to form distorted AlSc3Pd4 tetrahedra that share corners with six equivalent PdSc4Al8 cuboctahedra, corners with seven equivalent AlSc3Pd4 tetrahedra, edges with three equivalent PdSc4Al8 cuboctahedra, edges with three equivalent AlSc3Pd4 tetrahedra, and faces with three equivalent AlSc3Pd4 tetrahedra.