Tb(NbSn)6 crystallizes in the hexagonal P6/mmm space group. Tb(1) is bonded to two equivalent Sn(3) and six equivalent Sn(2) atoms to form distorted edge-sharing TbSn8 hexagonal bipyramids. Nb(1) is bonded in a 6-coordinate geometry to two equivalent Sn(1), two equivalent Sn(2), and two equivalent Sn(3) atoms. There are three inequivalent Sn sites. In the first Sn site, Sn(1) is bonded in a 6-coordinate geometry to six equivalent Nb(1) atoms. In the second Sn site, Sn(2) is bonded in a 9-coordinate geometry to three equivalent Tb(1) and six equivalent Nb(1) atoms. In the third Sn site, Sn(3) is bonded in a 8-coordinate geometry to one Tb(1), six equivalent Nb(1), and one Sn(3) atom.
Tb(NbSn)6 crystallizes in the hexagonal P6/mmm space group. Tb(1) is bonded to two equivalent Sn(3) and six equivalent Sn(2) atoms to form distorted edge-sharing TbSn8 hexagonal bipyramids. Both Tb(1)-Sn(3) bond lengths are 3.15 Å. All Tb(1)-Sn(2) bond lengths are 3.35 Å. Nb(1) is bonded in a 6-coordinate geometry to two equivalent Sn(1), two equivalent Sn(2), and two equivalent Sn(3) atoms. Both Nb(1)-Sn(1) bond lengths are 2.93 Å. Both Nb(1)-Sn(2) bond lengths are 2.92 Å. Both Nb(1)-Sn(3) bond lengths are 3.00 Å. There are three inequivalent Sn sites. In the first Sn site, Sn(1) is bonded in a 6-coordinate geometry to six equivalent Nb(1) atoms. In the second Sn site, Sn(2) is bonded in a 9-coordinate geometry to three equivalent Tb(1) and six equivalent Nb(1) atoms. In the third Sn site, Sn(3) is bonded in a 8-coordinate geometry to one Tb(1), six equivalent Nb(1), and one Sn(3) atom. The Sn(3)-Sn(3) bond length is 3.28 Å.