EuCu5 crystallizes in the hexagonal P6/mmm space group. Eu(1) is bonded in a 18-coordinate geometry to six equivalent Cu(2) and twelve equivalent Cu(1) atoms. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to four equivalent Eu(1), four equivalent Cu(1), and four equivalent Cu(2) atoms to form a mixture of edge, face, and corner-sharing CuEu4Cu8 cuboctahedra. In the second Cu site, Cu(2) is bonded in a 9-coordinate geometry to three equivalent Eu(1) and six equivalent Cu(1) atoms.
EuCu5 crystallizes in the hexagonal P6/mmm space group. Eu(1) is bonded in a 18-coordinate geometry to six equivalent Cu(2) and twelve equivalent Cu(1) atoms. All Eu(1)-Cu(2) bond lengths are 2.95 Å. All Eu(1)-Cu(1) bond lengths are 3.25 Å. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to four equivalent Eu(1), four equivalent Cu(1), and four equivalent Cu(2) atoms to form a mixture of edge, face, and corner-sharing CuEu4Cu8 cuboctahedra. All Cu(1)-Cu(1) bond lengths are 2.55 Å. All Cu(1)-Cu(2) bond lengths are 2.49 Å. In the second Cu site, Cu(2) is bonded in a 9-coordinate geometry to three equivalent Eu(1) and six equivalent Cu(1) atoms.