Materials Data on Cu15Si4 by Materials Project
Cu15Si4 crystallizes in the cubic I-43d space group. The structure is three-dimensional. there are two inequivalent Cu+1.07+ sites. In the first Cu+1.07+ site, Cu+1.07+ is bonded in a 12-coordinate geometry to eight equivalent Cu+1.07+ and four equivalent Si4- atoms. There are four shorter (2.49 Å) and four longer (2.59 Å) Cu–Cu bond lengths. All Cu–Si bond lengths are 2.62 Å. In the second Cu+1.07+ site, Cu+1.07+ is bonded in a 9-coordinate geometry to six Cu+1.07+ and three equivalent Si4- atoms. There are two shorter (2.49 Å) and two longer (2.57 Å) Cu–Cu bond lengths. There are a spread of Cu–Si bond distances ranging from 2.43–2.58 Å. Si4- is bonded to twelve Cu+1.07+ atoms to form a mixture of face and edge-sharing SiCu12 cuboctahedra.