Materials Data on K4Ge2Au7 by Materials Project
K4Au7Ge2 crystallizes in the trigonal R-3m space group. The structure is three-dimensional. there are two inequivalent K sites. In the first K site, K is bonded in a 12-coordinate geometry to twelve Au atoms. There are a spread of K–Au bond distances ranging from 3.52–3.84 Å. In the second K site, K is bonded in a 9-coordinate geometry to nine equivalent Au atoms. There are three shorter (3.50 Å) and six longer (3.78 Å) K–Au bond lengths. There are two inequivalent Au sites. In the first Au site, Au is bonded to six equivalent K and six equivalent Au atoms to form edge-sharing AuK6Au6 cuboctahedra. All Au–Au bond lengths are 2.82 Å. In the second Au site, Au is bonded in a 1-coordinate geometry to six K, one Au, and one Ge atom. The Au–Ge bond length is 2.48 Å. Ge is bonded in a 3-coordinate geometry to three equivalent Au atoms.