Sm2Cu4Sn5 crystallizes in the tetragonal I4mm space group. There are two inequivalent Sm sites. In the first Sm site, Sm(1) is bonded in a 16-coordinate geometry to four equivalent Cu(1), four equivalent Cu(2), four equivalent Cu(3), and four equivalent Sn(2) atoms. In the second Sm site, Sm(2) is bonded in a 13-coordinate geometry to one Cu(1), four equivalent Cu(2), four equivalent Sn(1), and four equivalent Sn(3) atoms. There are three inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a 10-coordinate geometry to one Sm(2), four equivalent Sm(1), one Cu(3), and four equivalent Cu(2) atoms. In the second Cu site, Cu(2) is bonded in a 8-coordinate geometry to two equivalent Sm(1), two equivalent Sm(2), two equivalent Cu(1), and two equivalent Sn(3) atoms. In the third Cu site, Cu(3) is bonded in a 9-coordinate geometry to four equivalent Sm(1), one Cu(1), and four equivalent Sn(2) atoms. There are three inequivalent Sn sites. In the first Sn site, Sn(1) is bonded in a 7-coordinate geometry to two equivalent Sm(2), one Sn(2), and four equivalent Sn(1) atoms. In the second Sn site, Sn(2) is bonded in a 9-coordinate geometry to two equivalent Sm(1), two equivalent Cu(3), one Sn(1), and four equivalent Sn(2) atoms. In the third Sn site, Sn(3) is bonded in a 8-coordinate geometry to four equivalent Sm(2) and four equivalent Cu(2) atoms.
Sm2Cu4Sn5 crystallizes in the tetragonal I4mm space group. There are two inequivalent Sm sites. In the first Sm site, Sm(1) is bonded in a 16-coordinate geometry to four equivalent Cu(1), four equivalent Cu(2), four equivalent Cu(3), and four equivalent Sn(2) atoms. All Sm(1)-Cu(1) bond lengths are 3.33 Å. All Sm(1)-Cu(2) bond lengths are 3.14 Å. All Sm(1)-Cu(3) bond lengths are 3.35 Å. All Sm(1)-Sn(2) bond lengths are 3.47 Å. In the second Sm site, Sm(2) is bonded in a 13-coordinate geometry to one Cu(1), four equivalent Cu(2), four equivalent Sn(1), and four equivalent Sn(3) atoms. The Sm(2)-Cu(1) bond length is 3.36 Å. All Sm(2)-Cu(2) bond lengths are 3.18 Å. All Sm(2)-Sn(1) bond lengths are 3.28 Å. All Sm(2)-Sn(3) bond lengths are 3.23 Å. There are three inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a 10-coordinate geometry to one Sm(2), four equivalent Sm(1), one Cu(3), and four equivalent Cu(2) atoms. The Cu(1)-Cu(3) bond length is 2.36 Å. All Cu(1)-Cu(2) bond lengths are 2.46 Å. In the second Cu site, Cu(2) is bonded in a 8-coordinate geometry to two equivalent Sm(1), two equivalent Sm(2), two equivalent Cu(1), and two equivalent Sn(3) atoms. Both Cu(2)-Sn(3) bond lengths are 2.66 Å. In the third Cu site, Cu(3) is bonded in a 9-coordinate geometry to four equivalent Sm(1), one Cu(1), and four equivalent Sn(2) atoms. All Cu(3)-Sn(2) bond lengths are 2.66 Å. There are three inequivalent Sn sites. In the first Sn site, Sn(1) is bonded in a 7-coordinate geometry to two equivalent Sm(2), one Sn(2), and four equivalent Sn(1) atoms. The Sn(1)-Sn(2) bond length is 2.91 Å. All Sn(1)-Sn(1) bond lengths are 3.13 Å. In the second Sn site, Sn(2) is bonded in a 9-coordinate geometry to two equivalent Sm(1), two equivalent Cu(3), one Sn(1), and four equivalent Sn(2) atoms. All Sn(2)-Sn(2) bond lengths are 3.13 Å. In the third Sn site, Sn(3) is bonded in a 8-coordinate geometry to four equivalent Sm(2) and four equivalent Cu(2) atoms.