Materials Data on YbAl2Cu by Materials Project
YbCuAl2 crystallizes in the trigonal R-3m space group. The structure is three-dimensional. there are two inequivalent Yb sites. In the first Yb site, Yb is bonded in a 6-coordinate geometry to six equivalent Cu and twelve equivalent Al atoms. All Yb–Cu bond lengths are 3.15 Å. All Yb–Al bond lengths are 3.41 Å. In the second Yb site, Yb is bonded in a 12-coordinate geometry to three equivalent Cu and nine equivalent Al atoms. All Yb–Cu bond lengths are 3.20 Å. All Yb–Al bond lengths are 3.21 Å. There are two inequivalent Cu sites. In the first Cu site, Cu is bonded in a 9-coordinate geometry to three equivalent Yb and six equivalent Al atoms. There are three shorter (2.55 Å) and three longer (2.60 Å) Cu–Al bond lengths. In the second Cu site, Cu is bonded to six equivalent Yb and six equivalent Al atoms to form CuYb6Al6 cuboctahedra that share corners with twelve equivalent AlYb5Al4Cu3 cuboctahedra, edges with six equivalent CuYb6Al6 cuboctahedra, and faces with eighteen equivalent AlYb5Al4Cu3 cuboctahedra. All Cu–Al bond lengths are 2.74 Å. Al is bonded to five Yb, three Cu, and four equivalent Al atoms to form distorted AlYb5Al4Cu3 cuboctahedra that share corners with two equivalent CuYb6Al6 cuboctahedra, corners with fifteen equivalent AlYb5Al4Cu3 cuboctahedra, edges with eight equivalent AlYb5Al4Cu3 cuboctahedra, faces with three equivalent CuYb6Al6 cuboctahedra, and faces with eleven equivalent AlYb5Al4Cu3 cuboctahedra. There are two shorter (2.72 Å) and two longer (2.73 Å) Al–Al bond lengths.