Ho3Sn7 crystallizes in the orthorhombic Cmmm space group. There are two inequivalent Ho sites. In the first Ho site, Ho(1) is bonded to four equivalent Sn(1), four equivalent Sn(2), and four equivalent Sn(3) atoms to form a mixture of corner and face-sharing HoSn12 cuboctahedra. In the second Ho site, Ho(2) is bonded in a 10-coordinate geometry to two equivalent Sn(2), two equivalent Sn(3), and six equivalent Sn(4) atoms. There are four inequivalent Sn sites. In the first Sn site, Sn(1) is bonded in a square co-planar geometry to four equivalent Ho(1), four equivalent Sn(2), and four equivalent Sn(3) atoms. In the second Sn site, Sn(2) is bonded in a 10-coordinate geometry to two equivalent Ho(1), two equivalent Ho(2), two equivalent Sn(1), and four equivalent Sn(3) atoms. In the third Sn site, Sn(3) is bonded in a 10-coordinate geometry to two equivalent Ho(1), two equivalent Ho(2), two equivalent Sn(1), and four equivalent Sn(2) atoms. In the fourth Sn site, Sn(4) is bonded in a 8-coordinate geometry to six equivalent Ho(2) and two equivalent Sn(4) atoms.
Ho3Sn7 crystallizes in the orthorhombic Cmmm space group. There are two inequivalent Ho sites. In the first Ho site, Ho(1) is bonded to four equivalent Sn(1), four equivalent Sn(2), and four equivalent Sn(3) atoms to form a mixture of corner and face-sharing HoSn12 cuboctahedra. All Ho(1)-Sn(1) bond lengths are 3.10 Å. All Ho(1)-Sn(2) bond lengths are 3.37 Å. All Ho(1)-Sn(3) bond lengths are 3.38 Å. In the second Ho site, Ho(2) is bonded in a 10-coordinate geometry to two equivalent Sn(2), two equivalent Sn(3), and six equivalent Sn(4) atoms. Both Ho(2)-Sn(2) bond lengths are 3.28 Å. Both Ho(2)-Sn(3) bond lengths are 3.27 Å. There are four shorter (3.17 Å) and two longer (3.44 Å) Ho(2)-Sn(4) bond lengths. There are four inequivalent Sn sites. In the first Sn site, Sn(1) is bonded in a square co-planar geometry to four equivalent Ho(1), four equivalent Sn(2), and four equivalent Sn(3) atoms. All Sn(1)-Sn(2) bond lengths are 3.39 Å. All Sn(1)-Sn(3) bond lengths are 3.37 Å. In the second Sn site, Sn(2) is bonded in a 10-coordinate geometry to two equivalent Ho(1), two equivalent Ho(2), two equivalent Sn(1), and four equivalent Sn(3) atoms. All Sn(2)-Sn(3) bond lengths are 3.10 Å. In the third Sn site, Sn(3) is bonded in a 10-coordinate geometry to two equivalent Ho(1), two equivalent Ho(2), two equivalent Sn(1), and four equivalent Sn(2) atoms. In the fourth Sn site, Sn(4) is bonded in a 8-coordinate geometry to six equivalent Ho(2) and two equivalent Sn(4) atoms. Both Sn(4)-Sn(4) bond lengths are 2.96 Å.