Tb3Sc2S7 crystallizes in the monoclinic C2/m space group. There are two inequivalent Tb sites. In the first Tb site, Tb(1) is bonded in a 7-coordinate geometry to two equivalent S(1), two equivalent S(3), and three equivalent S(2) atoms. In the second Tb site, Tb(2) is bonded to two equivalent S(3) and four equivalent S(2) atoms to form TbS6 octahedra that share corners with two equivalent Sc(1)S6 octahedra and edges with two equivalent Tb(2)S6 octahedra. The corner-sharing octahedral tilt angles are 51°. Sc(1) is bonded to one S(3), two equivalent S(4), and three equivalent S(1) atoms to form ScS6 octahedra that share  a cornercorner with one Tb(2)S6 octahedra, corners with two equivalent Sc(1)S6 octahedra, and edges with five equivalent Sc(1)S6 octahedra. The corner-sharing octahedral tilt angles range from 0-51°. There are four inequivalent S sites. In the first S site, S(1) is bonded to two equivalent Tb(1) and three equivalent Sc(1) atoms to form STb2Sc3 trigonal bipyramids that share corners with five equivalent S(3)Tb3Sc tetrahedra, corners with four equivalent S(2)Tb5 trigonal bipyramids,  an edgeedge with one S(3)Tb3Sc tetrahedra,  an edgeedge with one S(2)Tb5 trigonal bipyramid, and edges with four equivalent S(1)Tb2Sc3 trigonal bipyramids. In the second S site, S(2) is bonded to two equivalent Tb(2) and three equivalent Tb(1) atoms to form distorted STb5 trigonal bipyramids that share corners with four equivalent S(3)Tb3Sc tetrahedra, corners with two equivalent S(2)Tb5 trigonal bipyramids, corners with four equivalent S(1)Tb2Sc3 trigonal bipyramids, edges with three equivalent S(3)Tb3Sc tetrahedra,  an edgeedge with one S(1)Tb2Sc3 trigonal bipyramid, and edges with five equivalent S(2)Tb5 trigonal bipyramids. In the third S site, S(3) is bonded to one Tb(2), two equivalent Tb(1), and one Sc(1) atom to form distorted STb3Sc tetrahedra that share corners with three equivalent S(3)Tb3Sc tetrahedra, corners with four equivalent S(2)Tb5 trigonal bipyramids, corners with five equivalent S(1)Tb2Sc3 trigonal bipyramids,  an edgeedge with one S(1)Tb2Sc3 trigonal bipyramid, and edges with three equivalent S(2)Tb5 trigonal bipyramids. In the fourth S site, S(4) is bonded in a square co-planar geometry to four equivalent Sc(1) atoms.
Tb3Sc2S7 crystallizes in the monoclinic C2/m space group. There are two inequivalent Tb sites. In the first Tb site, Tb(1) is bonded in a 7-coordinate geometry to two equivalent S(1), two equivalent S(3), and three equivalent S(2) atoms. Both Tb(1)-S(1) bond lengths are 2.90 Å. Both Tb(1)-S(3) bond lengths are 2.73 Å. There are two shorter (2.81 Å) and one longer (3.05 Å) Tb(1)-S(2) bond length. In the second Tb site, Tb(2) is bonded to two equivalent S(3) and four equivalent S(2) atoms to form TbS6 octahedra that share corners with two equivalent Sc(1)S6 octahedra and edges with two equivalent Tb(2)S6 octahedra. The corner-sharing octahedral tilt angles are 51°. Both Tb(2)-S(3) bond lengths are 2.69 Å. All Tb(2)-S(2) bond lengths are 2.71 Å. Sc(1) is bonded to one S(3), two equivalent S(4), and three equivalent S(1) atoms to form ScS6 octahedra that share  a cornercorner with one Tb(2)S6 octahedra, corners with two equivalent Sc(1)S6 octahedra, and edges with five equivalent Sc(1)S6 octahedra. The corner-sharing octahedral tilt angles range from 0-51°. The Sc(1)-S(3) bond length is 2.55 Å. Both Sc(1)-S(4) bond lengths are 2.58 Å. There is one shorter (2.62 Å) and two longer (2.67 Å) Sc(1)-S(1) bond lengths. There are four inequivalent S sites. In the first S site, S(1) is bonded to two equivalent Tb(1) and three equivalent Sc(1) atoms to form STb2Sc3 trigonal bipyramids that share corners with five equivalent S(3)Tb3Sc tetrahedra, corners with four equivalent S(2)Tb5 trigonal bipyramids,  an edgeedge with one S(3)Tb3Sc tetrahedra,  an edgeedge with one S(2)Tb5 trigonal bipyramid, and edges with four equivalent S(1)Tb2Sc3 trigonal bipyramids. In the second S site, S(2) is bonded to two equivalent Tb(2) and three equivalent Tb(1) atoms to form distorted STb5 trigonal bipyramids that share corners with four equivalent S(3)Tb3Sc tetrahedra, corners with two equivalent S(2)Tb5 trigonal bipyramids, corners with four equivalent S(1)Tb2Sc3 trigonal bipyramids, edges with three equivalent S(3)Tb3Sc tetrahedra,  an edgeedge with one S(1)Tb2Sc3 trigonal bipyramid, and edges with five equivalent S(2)Tb5 trigonal bipyramids. In the third S site, S(3) is bonded to one Tb(2), two equivalent Tb(1), and one Sc(1) atom to form distorted STb3Sc tetrahedra that share corners with three equivalent S(3)Tb3Sc tetrahedra, corners with four equivalent S(2)Tb5 trigonal bipyramids, corners with five equivalent S(1)Tb2Sc3 trigonal bipyramids,  an edgeedge with one S(1)Tb2Sc3 trigonal bipyramid, and edges with three equivalent S(2)Tb5 trigonal bipyramids. In the fourth S site, S(4) is bonded in a square co-planar geometry to four equivalent Sc(1) atoms.