Cu9Ga4 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(5) is bonded in a 13-coordinate geometry to one Cu(5), two equivalent Cu(2), two equivalent Cu(3), four equivalent Cu(6), and four equivalent Ga(2) atoms. In the second Cu site, Cu(6) is bonded in a 11-coordinate geometry to one Cu(1), one Cu(3), two equivalent Cu(4), two equivalent Cu(5), one Ga(1), and four equivalent Ga(2) atoms. In the third Cu site, Cu(1) is bonded in a 12-coordinate geometry to three equivalent Cu(4), three equivalent Cu(6), three equivalent Ga(1), and three equivalent Ga(2) atoms. In the fourth Cu site, Cu(2) is bonded in a 12-coordinate geometry to three equivalent Cu(2), three equivalent Cu(3), three equivalent Cu(5), and three equivalent Ga(2) atoms. In the fifth Cu site, Cu(3) is bonded in a 3-coordinate geometry to three equivalent Cu(2), three equivalent Cu(5), three equivalent Cu(6), and three equivalent Ga(2) atoms. In the sixth Cu site, Cu(4) is bonded in a 13-coordinate geometry to one Cu(4), two equivalent Cu(1), four equivalent Cu(6), two equivalent Ga(1), and four equivalent Ga(2) atoms. There are two inequivalent Ga sites. In the first Ga site, Ga(1) is bonded in a 9-coordinate geometry to three equivalent Cu(1), three equivalent Cu(4), and three equivalent Cu(6) atoms. In the second Ga site, Ga(2) is bonded in a 11-coordinate geometry to one Cu(1), one Cu(2), one Cu(3), two equivalent Cu(4), two equivalent Cu(5), and four equivalent Cu(6) atoms.
Cu9Ga4 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(5) is bonded in a 13-coordinate geometry to one Cu(5), two equivalent Cu(2), two equivalent Cu(3), four equivalent Cu(6), and four equivalent Ga(2) atoms. The Cu(5)-Cu(5) bond length is 2.52 Å. Both Cu(5)-Cu(2) bond lengths are 2.51 Å. Both Cu(5)-Cu(3) bond lengths are 2.64 Å. There are two shorter (2.45 Å) and two longer (2.70 Å) Cu(5)-Cu(6) bond lengths. All Cu(5)-Ga(2) bond lengths are 2.72 Å. In the second Cu site, Cu(6) is bonded in a 11-coordinate geometry to one Cu(1), one Cu(3), two equivalent Cu(4), two equivalent Cu(5), one Ga(1), and four equivalent Ga(2) atoms. The Cu(6)-Cu(1) bond length is 2.49 Å. The Cu(6)-Cu(3) bond length is 2.58 Å. Both Cu(6)-Cu(4) bond lengths are 2.77 Å. The Cu(6)-Ga(1) bond length is 2.51 Å. There are two shorter (2.55 Å) and two longer (2.58 Å) Cu(6)-Ga(2) bond lengths. In the third Cu site, Cu(1) is bonded in a 12-coordinate geometry to three equivalent Cu(4), three equivalent Cu(6), three equivalent Ga(1), and three equivalent Ga(2) atoms. All Cu(1)-Cu(4) bond lengths are 2.63 Å. All Cu(1)-Ga(1) bond lengths are 2.61 Å. All Cu(1)-Ga(2) bond lengths are 2.57 Å. In the fourth Cu site, Cu(2) is bonded in a 12-coordinate geometry to three equivalent Cu(2), three equivalent Cu(3), three equivalent Cu(5), and three equivalent Ga(2) atoms. All Cu(2)-Cu(2) bond lengths are 2.56 Å. All Cu(2)-Cu(3) bond lengths are 2.55 Å. All Cu(2)-Ga(2) bond lengths are 2.58 Å. In the fifth Cu site, Cu(3) is bonded in a 3-coordinate geometry to three equivalent Cu(2), three equivalent Cu(5), three equivalent Cu(6), and three equivalent Ga(2) atoms. All Cu(3)-Ga(2) bond lengths are 2.44 Å. In the sixth Cu site, Cu(4) is bonded in a 13-coordinate geometry to one Cu(4), two equivalent Cu(1), four equivalent Cu(6), two equivalent Ga(1), and four equivalent Ga(2) atoms. The Cu(4)-Cu(4) bond length is 2.51 Å. Both Cu(4)-Ga(1) bond lengths are 2.51 Å. There are two shorter (2.53 Å) and two longer (2.80 Å) Cu(4)-Ga(2) bond lengths. There are two inequivalent Ga sites. In the first Ga site, Ga(1) is bonded in a 9-coordinate geometry to three equivalent Cu(1), three equivalent Cu(4), and three equivalent Cu(6) atoms. In the second Ga site, Ga(2) is bonded in a 11-coordinate geometry to one Cu(1), one Cu(2), one Cu(3), two equivalent Cu(4), two equivalent Cu(5), and four equivalent Cu(6) atoms.