Materials Data on K7NaGe8 by Materials Project
K7NaGe8 crystallizes in the cubic Pa-3 space group. The structure is three-dimensional. there are two inequivalent K sites. In the first K site, K is bonded in a 6-coordinate geometry to six Ge atoms. There are a spread of K–Ge bond distances ranging from 3.41–3.68 Å. In the second K site, K is bonded in a distorted octahedral geometry to six equivalent Ge atoms. All K–Ge bond lengths are 3.96 Å. Na is bonded in a 6-coordinate geometry to six equivalent Ge atoms. All Na–Ge bond lengths are 2.95 Å. There are two inequivalent Ge sites. In the first Ge site, Ge is bonded in a 9-coordinate geometry to five K, one Na, and three Ge atoms. There are one shorter (2.57 Å) and two longer (2.66 Å) Ge–Ge bond lengths. In the second Ge site, Ge is bonded in a 9-coordinate geometry to six equivalent K and three equivalent Ge atoms.