Materials Data on BaCu9Ge4 by Materials Project
BaCu9Ge4 crystallizes in the tetragonal I4/mcm space group. The structure is three-dimensional. Ba is bonded in a 8-coordinate geometry to sixteen Cu and eight equivalent Ge atoms. There are eight shorter (3.47 Å) and eight longer (3.50 Å) Ba–Cu bond lengths. All Ba–Ge bond lengths are 3.45 Å. There are three inequivalent Cu sites. In the first Cu site, Cu is bonded in a 12-coordinate geometry to two equivalent Ba, six Cu, and four equivalent Ge atoms. There are a spread of Cu–Cu bond distances ranging from 2.55–2.77 Å. There are a spread of Cu–Ge bond distances ranging from 2.52–2.62 Å. In the second Cu site, Cu is bonded in a 12-coordinate geometry to two equivalent Ba, six Cu, and four equivalent Ge atoms. There are three shorter (2.53 Å) and one longer (2.77 Å) Cu–Cu bond lengths. There are two shorter (2.63 Å) and two longer (2.67 Å) Cu–Ge bond lengths. In the third Cu site, Cu is bonded in a cuboctahedral geometry to eight Cu and four equivalent Ge atoms. All Cu–Ge bond lengths are 2.57 Å. Ge is bonded in a 12-coordinate geometry to two equivalent Ba, nine Cu, and one Ge atom. The Ge–Ge bond length is 2.91 Å.