Cu9In4 is gamma-brass-like structured and crystallizes in the cubic P-43m space group. There are six inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a 11-coordinate geometry to one Cu(4), one Cu(6), two equivalent Cu(2), two equivalent Cu(3), one In(2), and four equivalent In(1) atoms. In the second Cu site, Cu(2) is bonded in a 13-coordinate geometry to one Cu(2), two equivalent Cu(6), four equivalent Cu(1), two equivalent In(2), and four equivalent In(1) atoms. In the third Cu site, Cu(3) is bonded in a 13-coordinate geometry to one Cu(3), two equivalent Cu(4), two equivalent Cu(5), four equivalent Cu(1), and four equivalent In(1) atoms. In the fourth Cu site, Cu(4) is bonded in a 13-coordinate geometry to three equivalent Cu(1), three equivalent Cu(3), three equivalent Cu(5), one In(2), and three equivalent In(1) atoms. In the fifth Cu site, Cu(5) is bonded in a distorted q6 geometry to three equivalent Cu(3), three equivalent Cu(4), three equivalent Cu(5), and three equivalent In(1) atoms. In the sixth Cu site, Cu(6) is bonded to three equivalent Cu(1), three equivalent Cu(2), three equivalent In(1), and three equivalent In(2) atoms to form distorted face-sharing CuIn6Cu6 cuboctahedra. There are two inequivalent In sites. In the first In site, In(1) is bonded in a 11-coordinate geometry to one Cu(4), one Cu(5), one Cu(6), two equivalent Cu(2), two equivalent Cu(3), and four equivalent Cu(1) atoms. In the second In site, In(2) is bonded in a 9-coordinate geometry to one Cu(4), three equivalent Cu(1), three equivalent Cu(2), and three equivalent Cu(6) atoms.
Cu9In4 is gamma-brass-like structured and crystallizes in the cubic P-43m space group. There are six inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a 11-coordinate geometry to one Cu(4), one Cu(6), two equivalent Cu(2), two equivalent Cu(3), one In(2), and four equivalent In(1) atoms. The Cu(1)-Cu(4) bond length is 2.75 Å. The Cu(1)-Cu(6) bond length is 2.70 Å. Both Cu(1)-Cu(2) bond lengths are 2.98 Å. There is one shorter (2.54 Å) and one longer (2.83 Å) Cu(1)-Cu(3) bond length. The Cu(1)-In(2) bond length is 2.67 Å. There are two shorter (2.71 Å) and two longer (2.73 Å) Cu(1)-In(1) bond lengths. In the second Cu site, Cu(2) is bonded in a 13-coordinate geometry to one Cu(2), two equivalent Cu(6), four equivalent Cu(1), two equivalent In(2), and four equivalent In(1) atoms. The Cu(2)-Cu(2) bond length is 2.60 Å. Both Cu(2)-Cu(6) bond lengths are 2.80 Å. Both Cu(2)-In(2) bond lengths are 2.69 Å. There are two shorter (2.67 Å) and two longer (2.98 Å) Cu(2)-In(1) bond lengths. In the third Cu site, Cu(3) is bonded in a 13-coordinate geometry to one Cu(3), two equivalent Cu(4), two equivalent Cu(5), four equivalent Cu(1), and four equivalent In(1) atoms. The Cu(3)-Cu(3) bond length is 2.63 Å. Both Cu(3)-Cu(4) bond lengths are 2.80 Å. Both Cu(3)-Cu(5) bond lengths are 2.70 Å. All Cu(3)-In(1) bond lengths are 2.89 Å. In the fourth Cu site, Cu(4) is bonded in a 13-coordinate geometry to three equivalent Cu(1), three equivalent Cu(3), three equivalent Cu(5), one In(2), and three equivalent In(1) atoms. All Cu(4)-Cu(5) bond lengths are 2.63 Å. The Cu(4)-In(2) bond length is 3.24 Å. All Cu(4)-In(1) bond lengths are 2.61 Å. In the fifth Cu site, Cu(5) is bonded in a distorted q6 geometry to three equivalent Cu(3), three equivalent Cu(4), three equivalent Cu(5), and three equivalent In(1) atoms. All Cu(5)-Cu(5) bond lengths are 2.55 Å. All Cu(5)-In(1) bond lengths are 2.79 Å. In the sixth Cu site, Cu(6) is bonded to three equivalent Cu(1), three equivalent Cu(2), three equivalent In(1), and three equivalent In(2) atoms to form distorted face-sharing CuIn6Cu6 cuboctahedra. All Cu(6)-In(1) bond lengths are 2.73 Å. All Cu(6)-In(2) bond lengths are 2.77 Å. There are two inequivalent In sites. In the first In site, In(1) is bonded in a 11-coordinate geometry to one Cu(4), one Cu(5), one Cu(6), two equivalent Cu(2), two equivalent Cu(3), and four equivalent Cu(1) atoms. In the second In site, In(2) is bonded in a 9-coordinate geometry to one Cu(4), three equivalent Cu(1), three equivalent Cu(2), and three equivalent Cu(6) atoms.