Y3Cu4Ga7 crystallizes in the monoclinic C2/m space group. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded in a 15-coordinate geometry to two equivalent Cu(1), three equivalent Cu(2), two equivalent Ga(3), two equivalent Ga(4), three equivalent Ga(1), and three equivalent Ga(2) atoms. In the second Y site, Y(2) is bonded to four equivalent Cu(2), two equivalent Ga(1), two equivalent Ga(2), and four equivalent Ga(4) atoms to form distorted YGa8Cu4 cuboctahedra that share edges with two equivalent Ga(3)Y4Ga4Cu4 cuboctahedra and faces with two equivalent Y(2)Ga8Cu4 cuboctahedra. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a 10-coordinate geometry to two equivalent Y(1), one Cu(2), one Ga(4), two equivalent Ga(1), two equivalent Ga(2), and two equivalent Ga(3) atoms. In the second Cu site, Cu(2) is bonded in a 9-coordinate geometry to two equivalent Y(2), three equivalent Y(1), one Cu(1), one Ga(4), and three equivalent Ga(2) atoms. There are four inequivalent Ga sites. In the first Ga site, Ga(1) is bonded in a 10-coordinate geometry to one Y(2), three equivalent Y(1), two equivalent Cu(1), one Ga(3), and three equivalent Ga(4) atoms. In the second Ga site, Ga(2) is bonded in a 10-coordinate geometry to one Y(2), three equivalent Y(1), two equivalent Cu(1), three equivalent Cu(2), and one Ga(3) atom. In the third Ga site, Ga(3) is bonded to four equivalent Y(1), four equivalent Cu(1), two equivalent Ga(1), and two equivalent Ga(2) atoms to form GaY4Ga4Cu4 cuboctahedra that share edges with two equivalent Y(2)Ga8Cu4 cuboctahedra and faces with two equivalent Ga(3)Y4Ga4Cu4 cuboctahedra. In the fourth Ga site, Ga(4) is bonded in a 9-coordinate geometry to two equivalent Y(1), two equivalent Y(2), one Cu(1), one Cu(2), and three equivalent Ga(1) atoms.
Y3Cu4Ga7 crystallizes in the monoclinic C2/m space group. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded in a 15-coordinate geometry to two equivalent Cu(1), three equivalent Cu(2), two equivalent Ga(3), two equivalent Ga(4), three equivalent Ga(1), and three equivalent Ga(2) atoms. There is one shorter (3.03 Å) and one longer (3.08 Å) Y(1)-Cu(1) bond length. There are two shorter (3.02 Å) and one longer (3.32 Å) Y(1)-Cu(2) bond length. Both Y(1)-Ga(3) bond lengths are 3.13 Å. Both Y(1)-Ga(4) bond lengths are 3.02 Å. There are two shorter (3.07 Å) and one longer (3.43 Å) Y(1)-Ga(1) bond length. There are two shorter (2.99 Å) and one longer (3.25 Å) Y(1)-Ga(2) bond length. In the second Y site, Y(2) is bonded to four equivalent Cu(2), two equivalent Ga(1), two equivalent Ga(2), and four equivalent Ga(4) atoms to form distorted YGa8Cu4 cuboctahedra that share edges with two equivalent Ga(3)Y4Ga4Cu4 cuboctahedra and faces with two equivalent Y(2)Ga8Cu4 cuboctahedra. All Y(2)-Cu(2) bond lengths are 3.14 Å. Both Y(2)-Ga(1) bond lengths are 3.13 Å. Both Y(2)-Ga(2) bond lengths are 3.06 Å. All Y(2)-Ga(4) bond lengths are 3.06 Å. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a 10-coordinate geometry to two equivalent Y(1), one Cu(2), one Ga(4), two equivalent Ga(1), two equivalent Ga(2), and two equivalent Ga(3) atoms. The Cu(1)-Cu(2) bond length is 2.49 Å. The Cu(1)-Ga(4) bond length is 2.52 Å. Both Cu(1)-Ga(1) bond lengths are 2.65 Å. Both Cu(1)-Ga(2) bond lengths are 2.71 Å. Both Cu(1)-Ga(3) bond lengths are 2.84 Å. In the second Cu site, Cu(2) is bonded in a 9-coordinate geometry to two equivalent Y(2), three equivalent Y(1), one Cu(1), one Ga(4), and three equivalent Ga(2) atoms. The Cu(2)-Ga(4) bond length is 2.43 Å. There are two shorter (2.43 Å) and one longer (2.63 Å) Cu(2)-Ga(2) bond length. There are four inequivalent Ga sites. In the first Ga site, Ga(1) is bonded in a 10-coordinate geometry to one Y(2), three equivalent Y(1), two equivalent Cu(1), one Ga(3), and three equivalent Ga(4) atoms. The Ga(1)-Ga(3) bond length is 2.69 Å. There are two shorter (2.57 Å) and one longer (2.68 Å) Ga(1)-Ga(4) bond length. In the second Ga site, Ga(2) is bonded in a 10-coordinate geometry to one Y(2), three equivalent Y(1), two equivalent Cu(1), three equivalent Cu(2), and one Ga(3) atom. The Ga(2)-Ga(3) bond length is 2.73 Å. In the third Ga site, Ga(3) is bonded to four equivalent Y(1), four equivalent Cu(1), two equivalent Ga(1), and two equivalent Ga(2) atoms to form GaY4Ga4Cu4 cuboctahedra that share edges with two equivalent Y(2)Ga8Cu4 cuboctahedra and faces with two equivalent Ga(3)Y4Ga4Cu4 cuboctahedra. In the fourth Ga site, Ga(4) is bonded in a 9-coordinate geometry to two equivalent Y(1), two equivalent Y(2), one Cu(1), one Cu(2), and three equivalent Ga(1) atoms.