Tb2Tl crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Tb sites. In the first Tb site, Tb(1) is bonded in a 14-coordinate geometry to two equivalent Tb(1), six equivalent Tb(2), and six equivalent Tl(1) atoms. In the second Tb site, Tb(2) is bonded to six equivalent Tb(1) and five equivalent Tl(1) atoms to form a mixture of distorted corner and face-sharing TbTb6Tl5 trigonal bipyramids. Tl(1) is bonded in a 11-coordinate geometry to five equivalent Tb(2) and six equivalent Tb(1) atoms.
Tb2Tl crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Tb sites. In the first Tb site, Tb(1) is bonded in a 14-coordinate geometry to two equivalent Tb(1), six equivalent Tb(2), and six equivalent Tl(1) atoms. Both Tb(1)-Tb(1) bond lengths are 3.36 Å. All Tb(1)-Tb(2) bond lengths are 3.54 Å. All Tb(1)-Tl(1) bond lengths are 3.54 Å. In the second Tb site, Tb(2) is bonded to six equivalent Tb(1) and five equivalent Tl(1) atoms to form a mixture of distorted corner and face-sharing TbTb6Tl5 trigonal bipyramids. There are three shorter (3.12 Å) and two longer (3.36 Å) Tb(2)-Tl(1) bond lengths. Tl(1) is bonded in a 11-coordinate geometry to five equivalent Tb(2) and six equivalent Tb(1) atoms.