Materials Data on Ba4Cu3Si20 by Materials Project
Ba4Cu3Si20 crystallizes in the cubic Pm-3n space group. The structure is three-dimensional. there are two inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded in a 8-coordinate geometry to twenty Si+0.80- atoms. There are eight shorter (3.30 Å) and twelve longer (3.45 Å) Ba–Si bond lengths. In the second Ba2+ site, Ba2+ is bonded in a 8-coordinate geometry to eight equivalent Si+0.80- atoms. All Ba–Si bond lengths are 3.47 Å. Cu+2.67+ is bonded in a tetrahedral geometry to four equivalent Si+0.80- atoms. All Cu–Si bond lengths are 2.38 Å. There are two inequivalent Si+0.80- sites. In the first Si+0.80- site, Si+0.80- is bonded in a 8-coordinate geometry to one Ba2+ and four Si+0.80- atoms. There are one shorter (2.38 Å) and three longer (2.41 Å) Si–Si bond lengths. In the second Si+0.80- site, Si+0.80- is bonded in a 7-coordinate geometry to three Ba2+, one Cu+2.67+, and three Si+0.80- atoms. The Si–Si bond length is 2.47 Å.