Materials Data on Y3Al7Cu2 by Materials Project
Y3Cu2Al7 crystallizes in the trigonal R-3m space group. The structure is three-dimensional. there are two inequivalent Y sites. In the first Y site, Y is bonded in a 6-coordinate geometry to six equivalent Cu atoms. All Y–Cu bond lengths are 3.18 Å. In the second Y site, Y is bonded in a 12-coordinate geometry to twelve Al atoms. There are a spread of Y–Al bond distances ranging from 3.19–3.27 Å. Cu is bonded in a 9-coordinate geometry to three equivalent Y and six equivalent Al atoms. There are three shorter (2.54 Å) and three longer (2.58 Å) Cu–Al bond lengths. There are two inequivalent Al sites. In the first Al site, Al is bonded in a 12-coordinate geometry to three equivalent Y, two equivalent Cu, and one Al atom. The Al–Al bond length is 2.76 Å. In the second Al site, Al is bonded to six equivalent Y and six equivalent Al atoms to form edge-sharing AlY6Al6 cuboctahedra.