Tb2MnS4 crystallizes in the orthorhombic Cmc2_1 space group. There are two inequivalent Tb sites. In the first Tb site, Tb(1) is bonded to one S(2), two equivalent S(1), two equivalent S(3), and two equivalent S(4) atoms to form distorted TbS7 pentagonal bipyramids that share corners with four equivalent Tb(2)S6 octahedra, corners with four equivalent Mn(1)S6 octahedra, edges with three equivalent Tb(2)S6 octahedra, edges with three equivalent Mn(1)S6 octahedra, and faces with two equivalent Tb(1)S7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 16-67°. In the second Tb site, Tb(2) is bonded to one S(3), one S(4), two equivalent S(1), and two equivalent S(2) atoms to form TbS6 octahedra that share corners with three equivalent Mn(1)S6 octahedra, corners with four equivalent Tb(1)S7 pentagonal bipyramids, edges with two equivalent Tb(2)S6 octahedra, edges with three equivalent Mn(1)S6 octahedra, and edges with three equivalent Tb(1)S7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 11-53°. Mn(1) is bonded to one S(1), one S(4), two equivalent S(2), and two equivalent S(3) atoms to form MnS6 octahedra that share corners with three equivalent Tb(2)S6 octahedra, corners with four equivalent Tb(1)S7 pentagonal bipyramids, edges with two equivalent Mn(1)S6 octahedra, edges with three equivalent Tb(2)S6 octahedra, and edges with three equivalent Tb(1)S7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 11-53°. There are four inequivalent S sites. In the first S site, S(1) is bonded to two equivalent Tb(1), two equivalent Tb(2), and one Mn(1) atom to form distorted STb4Mn trigonal bipyramids that share corners with two equivalent S(3)Tb3Mn2 square pyramids, corners with six equivalent S(2)Tb3Mn2 square pyramids, corners with five equivalent S(4)Tb3Mn tetrahedra,  an edgeedge with one S(2)Tb3Mn2 square pyramid, edges with three equivalent S(3)Tb3Mn2 square pyramids,  an edgeedge with one S(4)Tb3Mn tetrahedra, and edges with two equivalent S(1)Tb4Mn trigonal bipyramids. In the second S site, S(2) is bonded to one Tb(1), two equivalent Tb(2), and two equivalent Mn(1) atoms to form STb3Mn2 square pyramids that share corners with two equivalent S(3)Tb3Mn2 square pyramids, corners with two equivalent S(4)Tb3Mn tetrahedra, corners with six equivalent S(1)Tb4Mn trigonal bipyramids, edges with two equivalent S(2)Tb3Mn2 square pyramids, edges with three equivalent S(3)Tb3Mn2 square pyramids, edges with two equivalent S(4)Tb3Mn tetrahedra, and  an edgeedge with one S(1)Tb4Mn trigonal bipyramid. In the third S site, S(3) is bonded to one Tb(2), two equivalent Tb(1), and two equivalent Mn(1) atoms to form STb3Mn2 square pyramids that share corners with two equivalent S(2)Tb3Mn2 square pyramids, corners with five equivalent S(4)Tb3Mn tetrahedra, corners with two equivalent S(1)Tb4Mn trigonal bipyramids, edges with two equivalent S(3)Tb3Mn2 square pyramids, edges with three equivalent S(2)Tb3Mn2 square pyramids,  an edgeedge with one S(4)Tb3Mn tetrahedra, and edges with three equivalent S(1)Tb4Mn trigonal bipyramids. In the fourth S site, S(4) is bonded to one Tb(2), two equivalent Tb(1), and one Mn(1) atom to form STb3Mn tetrahedra that share corners with two equivalent S(2)Tb3Mn2 square pyramids, corners with five equivalent S(3)Tb3Mn2 square pyramids, corners with two equivalent S(4)Tb3Mn tetrahedra, corners with five equivalent S(1)Tb4Mn trigonal bipyramids,  an edgeedge with one S(3)Tb3Mn2 square pyramid, edges with two equivalent S(2)Tb3Mn2 square pyramids, and  an edgeedge with one S(1)Tb4Mn trigonal bipyramid.
Tb2MnS4 crystallizes in the orthorhombic Cmc2_1 space group. There are two inequivalent Tb sites. In the first Tb site, Tb(1) is bonded to one S(2), two equivalent S(1), two equivalent S(3), and two equivalent S(4) atoms to form distorted TbS7 pentagonal bipyramids that share corners with four equivalent Tb(2)S6 octahedra, corners with four equivalent Mn(1)S6 octahedra, edges with three equivalent Tb(2)S6 octahedra, edges with three equivalent Mn(1)S6 octahedra, and faces with two equivalent Tb(1)S7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 16-67°. The Tb(1)-S(2) bond length is 3.02 Å. Both Tb(1)-S(1) bond lengths are 2.93 Å. Both Tb(1)-S(3) bond lengths are 2.81 Å. Both Tb(1)-S(4) bond lengths are 2.72 Å. In the second Tb site, Tb(2) is bonded to one S(3), one S(4), two equivalent S(1), and two equivalent S(2) atoms to form TbS6 octahedra that share corners with three equivalent Mn(1)S6 octahedra, corners with four equivalent Tb(1)S7 pentagonal bipyramids, edges with two equivalent Tb(2)S6 octahedra, edges with three equivalent Mn(1)S6 octahedra, and edges with three equivalent Tb(1)S7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 11-53°. The Tb(2)-S(3) bond length is 2.72 Å. The Tb(2)-S(4) bond length is 2.71 Å. Both Tb(2)-S(1) bond lengths are 2.77 Å. Both Tb(2)-S(2) bond lengths are 2.71 Å. Mn(1) is bonded to one S(1), one S(4), two equivalent S(2), and two equivalent S(3) atoms to form MnS6 octahedra that share corners with three equivalent Tb(2)S6 octahedra, corners with four equivalent Tb(1)S7 pentagonal bipyramids, edges with two equivalent Mn(1)S6 octahedra, edges with three equivalent Tb(2)S6 octahedra, and edges with three equivalent Tb(1)S7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 11-53°. The Mn(1)-S(1) bond length is 2.64 Å. The Mn(1)-S(4) bond length is 2.53 Å. Both Mn(1)-S(2) bond lengths are 2.63 Å. Both Mn(1)-S(3) bond lengths are 2.61 Å. There are four inequivalent S sites. In the first S site, S(1) is bonded to two equivalent Tb(1), two equivalent Tb(2), and one Mn(1) atom to form distorted STb4Mn trigonal bipyramids that share corners with two equivalent S(3)Tb3Mn2 square pyramids, corners with six equivalent S(2)Tb3Mn2 square pyramids, corners with five equivalent S(4)Tb3Mn tetrahedra,  an edgeedge with one S(2)Tb3Mn2 square pyramid, edges with three equivalent S(3)Tb3Mn2 square pyramids,  an edgeedge with one S(4)Tb3Mn tetrahedra, and edges with two equivalent S(1)Tb4Mn trigonal bipyramids. In the second S site, S(2) is bonded to one Tb(1), two equivalent Tb(2), and two equivalent Mn(1) atoms to form STb3Mn2 square pyramids that share corners with two equivalent S(3)Tb3Mn2 square pyramids, corners with two equivalent S(4)Tb3Mn tetrahedra, corners with six equivalent S(1)Tb4Mn trigonal bipyramids, edges with two equivalent S(2)Tb3Mn2 square pyramids, edges with three equivalent S(3)Tb3Mn2 square pyramids, edges with two equivalent S(4)Tb3Mn tetrahedra, and  an edgeedge with one S(1)Tb4Mn trigonal bipyramid. In the third S site, S(3) is bonded to one Tb(2), two equivalent Tb(1), and two equivalent Mn(1) atoms to form STb3Mn2 square pyramids that share corners with two equivalent S(2)Tb3Mn2 square pyramids, corners with five equivalent S(4)Tb3Mn tetrahedra, corners with two equivalent S(1)Tb4Mn trigonal bipyramids, edges with two equivalent S(3)Tb3Mn2 square pyramids, edges with three equivalent S(2)Tb3Mn2 square pyramids,  an edgeedge with one S(4)Tb3Mn tetrahedra, and edges with three equivalent S(1)Tb4Mn trigonal bipyramids. In the fourth S site, S(4) is bonded to one Tb(2), two equivalent Tb(1), and one Mn(1) atom to form STb3Mn tetrahedra that share corners with two equivalent S(2)Tb3Mn2 square pyramids, corners with five equivalent S(3)Tb3Mn2 square pyramids, corners with two equivalent S(4)Tb3Mn tetrahedra, corners with five equivalent S(1)Tb4Mn trigonal bipyramids,  an edgeedge with one S(3)Tb3Mn2 square pyramid, edges with two equivalent S(2)Tb3Mn2 square pyramids, and  an edgeedge with one S(1)Tb4Mn trigonal bipyramid.