YbCu5Al crystallizes in the tetragonal I-4m2 space group. Yb(1) is bonded to twelve Cu(1,1,1) atoms to form a mixture of distorted face and edge-sharing YbCu12 cuboctahedra. There are four inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a 11-coordinate geometry to three equivalent Yb(1); two equivalent Cu(2); four Cu(1,1); and two equivalent Al(1) atoms. In the second Cu site, Cu(1) is bonded in a 11-coordinate geometry to three equivalent Yb(1); two equivalent Cu(2); four Cu(1,1); and two equivalent Al(1) atoms. In the third Cu site, Cu(1) is bonded in a 11-coordinate geometry to three equivalent Yb(1); two equivalent Cu(2); four Cu(1,1); and two equivalent Al(1) atoms. In the fourth Cu site, Cu(2) is bonded in a distorted linear geometry to eight Cu(1,1,1) and two equivalent Al(1) atoms. Al(1) is bonded in a 10-coordinate geometry to two equivalent Cu(2) and eight Cu(1,1,1) atoms.
YbCu5Al crystallizes in the tetragonal I-4m2 space group. Yb(1) is bonded to twelve Cu(1,1,1) atoms to form a mixture of distorted face and edge-sharing YbCu12 cuboctahedra. There are four shorter (2.72 Å) and eight longer (2.98 Å) Yb(1)-Cu(1,1,1) bond lengths. There are four inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a 11-coordinate geometry to three equivalent Yb(1); two equivalent Cu(2); four Cu(1,1); and two equivalent Al(1) atoms. Both Cu(1)-Cu(2) bond lengths are 2.58 Å. There are two shorter (2.44 Å) and two longer (2.63 Å) Cu(1)-Cu(1,1) bond lengths. Both Cu(1)-Al(1) bond lengths are 2.58 Å. In the second Cu site, Cu(1) is bonded in a 11-coordinate geometry to three equivalent Yb(1); two equivalent Cu(2); four Cu(1,1); and two equivalent Al(1) atoms. Both Cu(1)-Cu(2) bond lengths are 2.58 Å. Both Cu(1)-Cu(1) bond lengths are 2.44 Å. Both Cu(1)-Al(1) bond lengths are 2.58 Å. In the third Cu site, Cu(1) is bonded in a 11-coordinate geometry to three equivalent Yb(1); two equivalent Cu(2); four Cu(1,1); and two equivalent Al(1) atoms. Both Cu(1)-Cu(2) bond lengths are 2.58 Å. Both Cu(1)-Cu(1) bond lengths are 2.63 Å. Both Cu(1)-Al(1) bond lengths are 2.58 Å. In the fourth Cu site, Cu(2) is bonded in a distorted linear geometry to eight Cu(1,1,1) and two equivalent Al(1) atoms. Both Cu(2)-Al(1) bond lengths are 2.43 Å. Al(1) is bonded in a 10-coordinate geometry to two equivalent Cu(2) and eight Cu(1,1,1) atoms.