Y3Cu4Sn4 crystallizes in the orthorhombic Immm space group. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded to two equivalent Sn(1) and four equivalent Sn(2) atoms to form distorted edge-sharing YSn6 octahedra. In the second Y site, Y(2) is bonded in a 12-coordinate geometry to six equivalent Cu(1), two equivalent Sn(1), and four equivalent Sn(2) atoms. Cu(1) is bonded in a 8-coordinate geometry to three equivalent Y(2), one Cu(1), one Sn(2), and three equivalent Sn(1) atoms. There are two inequivalent Sn sites. In the first Sn site, Sn(1) is bonded in a 9-coordinate geometry to one Y(1), two equivalent Y(2), and six equivalent Cu(1) atoms. In the second Sn site, Sn(2) is bonded in a 9-coordinate geometry to two equivalent Y(1), four equivalent Y(2), two equivalent Cu(1), and one Sn(2) atom.
Y3Cu4Sn4 crystallizes in the orthorhombic Immm space group. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded to two equivalent Sn(1) and four equivalent Sn(2) atoms to form distorted edge-sharing YSn6 octahedra. Both Y(1)-Sn(1) bond lengths are 3.17 Å. All Y(1)-Sn(2) bond lengths are 3.04 Å. In the second Y site, Y(2) is bonded in a 12-coordinate geometry to six equivalent Cu(1), two equivalent Sn(1), and four equivalent Sn(2) atoms. All Y(2)-Cu(1) bond lengths are 3.16 Å. Both Y(2)-Sn(1) bond lengths are 3.15 Å. All Y(2)-Sn(2) bond lengths are 3.26 Å. Cu(1) is bonded in a 8-coordinate geometry to three equivalent Y(2), one Cu(1), one Sn(2), and three equivalent Sn(1) atoms. The Cu(1)-Cu(1) bond length is 2.59 Å. The Cu(1)-Sn(2) bond length is 2.63 Å. There are two shorter (2.66 Å) and one longer (2.72 Å) Cu(1)-Sn(1) bond length. There are two inequivalent Sn sites. In the first Sn site, Sn(1) is bonded in a 9-coordinate geometry to one Y(1), two equivalent Y(2), and six equivalent Cu(1) atoms. In the second Sn site, Sn(2) is bonded in a 9-coordinate geometry to two equivalent Y(1), four equivalent Y(2), two equivalent Cu(1), and one Sn(2) atom. The Sn(2)-Sn(2) bond length is 2.81 Å.