Tb6Cu23 crystallizes in the cubic Fm-3m space group. Tb(1) is bonded in a 12-coordinate geometry to four equivalent Cu(2), four equivalent Cu(3), and four equivalent Cu(4) atoms. There are four inequivalent Cu sites. In the first Cu site, Cu(4) is bonded in a distorted q6 geometry to three equivalent Tb(1), three equivalent Cu(2), three equivalent Cu(3), and three equivalent Cu(4) atoms. In the second Cu site, Cu(1) is bonded in a body-centered cubic geometry to eight equivalent Cu(3) atoms. In the third Cu site, Cu(2) is bonded to four equivalent Tb(1), four equivalent Cu(3), and four equivalent Cu(4) atoms to form a mixture of corner and face-sharing CuTb4Cu8 cuboctahedra. In the fourth Cu site, Cu(3) is bonded in a 13-coordinate geometry to three equivalent Tb(1), one Cu(1), three equivalent Cu(2), three equivalent Cu(3), and three equivalent Cu(4) atoms.
Tb6Cu23 crystallizes in the cubic Fm-3m space group. Tb(1) is bonded in a 12-coordinate geometry to four equivalent Cu(2), four equivalent Cu(3), and four equivalent Cu(4) atoms. All Tb(1)-Cu(2) bond lengths are 3.04 Å. All Tb(1)-Cu(3) bond lengths are 2.87 Å. All Tb(1)-Cu(4) bond lengths are 3.02 Å. There are four inequivalent Cu sites. In the first Cu site, Cu(4) is bonded in a distorted q6 geometry to three equivalent Tb(1), three equivalent Cu(2), three equivalent Cu(3), and three equivalent Cu(4) atoms. All Cu(4)-Cu(2) bond lengths are 2.47 Å. All Cu(4)-Cu(3) bond lengths are 2.59 Å. All Cu(4)-Cu(4) bond lengths are 2.56 Å. In the second Cu site, Cu(1) is bonded in a body-centered cubic geometry to eight equivalent Cu(3) atoms. All Cu(1)-Cu(3) bond lengths are 2.57 Å. In the third Cu site, Cu(2) is bonded to four equivalent Tb(1), four equivalent Cu(3), and four equivalent Cu(4) atoms to form a mixture of corner and face-sharing CuTb4Cu8 cuboctahedra. All Cu(2)-Cu(3) bond lengths are 2.62 Å. In the fourth Cu site, Cu(3) is bonded in a 13-coordinate geometry to three equivalent Tb(1), one Cu(1), three equivalent Cu(2), three equivalent Cu(3), and three equivalent Cu(4) atoms. All Cu(3)-Cu(3) bond lengths are 2.97 Å.