Tb2S3 crystallizes in the tetragonal I-42d space group. There are three inequivalent Tb sites. In the first Tb site, Tb(1) is bonded in a 8-coordinate geometry to two equivalent S(2), three equivalent S(1), and three equivalent S(3) atoms. In the second Tb site, Tb(2) is bonded in a 8-coordinate geometry to two equivalent S(2), two equivalent S(3), and four equivalent S(1) atoms. In the third Tb site, Tb(3) is bonded in a 8-coordinate geometry to two equivalent S(1), two equivalent S(3), and four equivalent S(2) atoms. There are three inequivalent S sites. In the first S site, S(1) is bonded to one Tb(3), two equivalent Tb(2), and three equivalent Tb(1) atoms to form distorted STb6 octahedra that share corners with three equivalent S(1)Tb6 octahedra, corners with seven equivalent S(3)Tb5 square pyramids, corners with five equivalent S(2)Tb5 trigonal bipyramids, edges with two equivalent S(1)Tb6 octahedra,  an edgeedge with one S(3)Tb5 square pyramid, edges with three equivalent S(2)Tb5 trigonal bipyramids, faces with two equivalent S(1)Tb6 octahedra, faces with two equivalent S(3)Tb5 square pyramids, and  a faceface with one S(2)Tb5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 21-47°. In the second S site, S(2) is bonded to one Tb(2), two equivalent Tb(1), and two equivalent Tb(3) atoms to form distorted STb5 trigonal bipyramids that share corners with five equivalent S(1)Tb6 octahedra, corners with four equivalent S(3)Tb5 square pyramids, corners with four equivalent S(2)Tb5 trigonal bipyramids, edges with three equivalent S(1)Tb6 octahedra, edges with four equivalent S(3)Tb5 square pyramids,  an edgeedge with one S(2)Tb5 trigonal bipyramid,  a faceface with one S(1)Tb6 octahedra, and  a faceface with one S(2)Tb5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 26-51°. In the third S site, S(3) is bonded to one Tb(2), one Tb(3), and three equivalent Tb(1) atoms to form distorted STb5 square pyramids that share corners with seven equivalent S(1)Tb6 octahedra, corners with five equivalent S(3)Tb5 square pyramids, corners with four equivalent S(2)Tb5 trigonal bipyramids,  an edgeedge with one S(1)Tb6 octahedra, edges with four equivalent S(2)Tb5 trigonal bipyramids, faces with two equivalent S(1)Tb6 octahedra, and  a faceface with one S(3)Tb5 square pyramid. The corner-sharing octahedral tilt angles range from 13-55°.
Tb2S3 crystallizes in the tetragonal I-42d space group. There are three inequivalent Tb sites. In the first Tb site, Tb(1) is bonded in a 8-coordinate geometry to two equivalent S(2), three equivalent S(1), and three equivalent S(3) atoms. There is one shorter (2.73 Å) and one longer (2.99 Å) Tb(1)-S(2) bond length. There are a spread of Tb(1)-S(1) bond distances ranging from 2.75-3.22 Å. There are a spread of Tb(1)-S(3) bond distances ranging from 2.72-3.01 Å. In the second Tb site, Tb(2) is bonded in a 8-coordinate geometry to two equivalent S(2), two equivalent S(3), and four equivalent S(1) atoms. Both Tb(2)-S(2) bond lengths are 2.75 Å. Both Tb(2)-S(3) bond lengths are 3.03 Å. There are two shorter (2.76 Å) and two longer (2.95 Å) Tb(2)-S(1) bond lengths. In the third Tb site, Tb(3) is bonded in a 8-coordinate geometry to two equivalent S(1), two equivalent S(3), and four equivalent S(2) atoms. Both Tb(3)-S(1) bond lengths are 3.09 Å. Both Tb(3)-S(3) bond lengths are 2.78 Å. There are two shorter (2.76 Å) and two longer (2.98 Å) Tb(3)-S(2) bond lengths. There are three inequivalent S sites. In the first S site, S(1) is bonded to one Tb(3), two equivalent Tb(2), and three equivalent Tb(1) atoms to form distorted STb6 octahedra that share corners with three equivalent S(1)Tb6 octahedra, corners with seven equivalent S(3)Tb5 square pyramids, corners with five equivalent S(2)Tb5 trigonal bipyramids, edges with two equivalent S(1)Tb6 octahedra,  an edgeedge with one S(3)Tb5 square pyramid, edges with three equivalent S(2)Tb5 trigonal bipyramids, faces with two equivalent S(1)Tb6 octahedra, faces with two equivalent S(3)Tb5 square pyramids, and  a faceface with one S(2)Tb5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 21-47°. In the second S site, S(2) is bonded to one Tb(2), two equivalent Tb(1), and two equivalent Tb(3) atoms to form distorted STb5 trigonal bipyramids that share corners with five equivalent S(1)Tb6 octahedra, corners with four equivalent S(3)Tb5 square pyramids, corners with four equivalent S(2)Tb5 trigonal bipyramids, edges with three equivalent S(1)Tb6 octahedra, edges with four equivalent S(3)Tb5 square pyramids,  an edgeedge with one S(2)Tb5 trigonal bipyramid,  a faceface with one S(1)Tb6 octahedra, and  a faceface with one S(2)Tb5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 26-51°. In the third S site, S(3) is bonded to one Tb(2), one Tb(3), and three equivalent Tb(1) atoms to form distorted STb5 square pyramids that share corners with seven equivalent S(1)Tb6 octahedra, corners with five equivalent S(3)Tb5 square pyramids, corners with four equivalent S(2)Tb5 trigonal bipyramids,  an edgeedge with one S(1)Tb6 octahedra, edges with four equivalent S(2)Tb5 trigonal bipyramids, faces with two equivalent S(1)Tb6 octahedra, and  a faceface with one S(3)Tb5 square pyramid. The corner-sharing octahedral tilt angles range from 13-55°.