Tm5S7 crystallizes in the monoclinic C2/m space group. There are three inequivalent Tm sites. In the first Tm site, Tm(1) is bonded to two equivalent S(3) and four equivalent S(2) atoms to form TmS6 octahedra that share corners with two equivalent Tm(2)S6 octahedra, corners with four equivalent Tm(3)S7 pentagonal bipyramids, edges with two equivalent Tm(1)S6 octahedra, and edges with six equivalent Tm(3)S7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 56°. In the second Tm site, Tm(2) is bonded to one S(3), two equivalent S(1), and three equivalent S(4) atoms to form TmS6 octahedra that share  a cornercorner with one Tm(1)S6 octahedra, corners with two equivalent Tm(2)S6 octahedra, corners with six equivalent Tm(3)S7 pentagonal bipyramids, edges with five equivalent Tm(2)S6 octahedra, and  an edgeedge with one Tm(3)S7 pentagonal bipyramid. The corner-sharing octahedral tilt angles range from 0-56°. In the third Tm site, Tm(3) is bonded to two equivalent S(3), two equivalent S(4), and three equivalent S(2) atoms to form distorted TmS7 pentagonal bipyramids that share corners with two equivalent Tm(1)S6 octahedra, corners with six equivalent Tm(2)S6 octahedra,  an edgeedge with one Tm(2)S6 octahedra, edges with three equivalent Tm(1)S6 octahedra, edges with two equivalent Tm(3)S7 pentagonal bipyramids, and faces with two equivalent Tm(3)S7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 22-67°. There are four inequivalent S sites. In the first S site, S(1) is bonded in a square co-planar geometry to four equivalent Tm(2) atoms. In the second S site, S(2) is bonded to two equivalent Tm(1) and three equivalent Tm(3) atoms to form distorted STm5 trigonal bipyramids that share corners with four equivalent S(3)Tm4 tetrahedra, corners with two equivalent S(2)Tm5 trigonal bipyramids, corners with four equivalent S(4)Tm5 trigonal bipyramids, edges with three equivalent S(3)Tm4 tetrahedra,  an edgeedge with one S(4)Tm5 trigonal bipyramid, and edges with five equivalent S(2)Tm5 trigonal bipyramids. In the third S site, S(3) is bonded to one Tm(1), one Tm(2), and two equivalent Tm(3) atoms to form distorted STm4 tetrahedra that share corners with three equivalent S(3)Tm4 tetrahedra, corners with four equivalent S(2)Tm5 trigonal bipyramids, corners with five equivalent S(4)Tm5 trigonal bipyramids,  an edgeedge with one S(4)Tm5 trigonal bipyramid, and edges with three equivalent S(2)Tm5 trigonal bipyramids. In the fourth S site, S(4) is bonded to two equivalent Tm(3) and three equivalent Tm(2) atoms to form STm5 trigonal bipyramids that share corners with five equivalent S(3)Tm4 tetrahedra, corners with four equivalent S(2)Tm5 trigonal bipyramids,  an edgeedge with one S(3)Tm4 tetrahedra,  an edgeedge with one S(2)Tm5 trigonal bipyramid, and edges with four equivalent S(4)Tm5 trigonal bipyramids.
Tm5S7 crystallizes in the monoclinic C2/m space group. There are three inequivalent Tm sites. In the first Tm site, Tm(1) is bonded to two equivalent S(3) and four equivalent S(2) atoms to form TmS6 octahedra that share corners with two equivalent Tm(2)S6 octahedra, corners with four equivalent Tm(3)S7 pentagonal bipyramids, edges with two equivalent Tm(1)S6 octahedra, and edges with six equivalent Tm(3)S7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 56°. Both Tm(1)-S(3) bond lengths are 2.63 Å. All Tm(1)-S(2) bond lengths are 2.69 Å. In the second Tm site, Tm(2) is bonded to one S(3), two equivalent S(1), and three equivalent S(4) atoms to form TmS6 octahedra that share  a cornercorner with one Tm(1)S6 octahedra, corners with two equivalent Tm(2)S6 octahedra, corners with six equivalent Tm(3)S7 pentagonal bipyramids, edges with five equivalent Tm(2)S6 octahedra, and  an edgeedge with one Tm(3)S7 pentagonal bipyramid. The corner-sharing octahedral tilt angles range from 0-56°. The Tm(2)-S(3) bond length is 2.65 Å. Both Tm(2)-S(1) bond lengths are 2.63 Å. There are two shorter (2.72 Å) and one longer (2.77 Å) Tm(2)-S(4) bond length. In the third Tm site, Tm(3) is bonded to two equivalent S(3), two equivalent S(4), and three equivalent S(2) atoms to form distorted TmS7 pentagonal bipyramids that share corners with two equivalent Tm(1)S6 octahedra, corners with six equivalent Tm(2)S6 octahedra,  an edgeedge with one Tm(2)S6 octahedra, edges with three equivalent Tm(1)S6 octahedra, edges with two equivalent Tm(3)S7 pentagonal bipyramids, and faces with two equivalent Tm(3)S7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 22-67°. Both Tm(3)-S(3) bond lengths are 2.70 Å. Both Tm(3)-S(4) bond lengths are 2.89 Å. There are two shorter (2.77 Å) and one longer (2.90 Å) Tm(3)-S(2) bond length. There are four inequivalent S sites. In the first S site, S(1) is bonded in a square co-planar geometry to four equivalent Tm(2) atoms. In the second S site, S(2) is bonded to two equivalent Tm(1) and three equivalent Tm(3) atoms to form distorted STm5 trigonal bipyramids that share corners with four equivalent S(3)Tm4 tetrahedra, corners with two equivalent S(2)Tm5 trigonal bipyramids, corners with four equivalent S(4)Tm5 trigonal bipyramids, edges with three equivalent S(3)Tm4 tetrahedra,  an edgeedge with one S(4)Tm5 trigonal bipyramid, and edges with five equivalent S(2)Tm5 trigonal bipyramids. In the third S site, S(3) is bonded to one Tm(1), one Tm(2), and two equivalent Tm(3) atoms to form distorted STm4 tetrahedra that share corners with three equivalent S(3)Tm4 tetrahedra, corners with four equivalent S(2)Tm5 trigonal bipyramids, corners with five equivalent S(4)Tm5 trigonal bipyramids,  an edgeedge with one S(4)Tm5 trigonal bipyramid, and edges with three equivalent S(2)Tm5 trigonal bipyramids. In the fourth S site, S(4) is bonded to two equivalent Tm(3) and three equivalent Tm(2) atoms to form STm5 trigonal bipyramids that share corners with five equivalent S(3)Tm4 tetrahedra, corners with four equivalent S(2)Tm5 trigonal bipyramids,  an edgeedge with one S(3)Tm4 tetrahedra,  an edgeedge with one S(2)Tm5 trigonal bipyramid, and edges with four equivalent S(4)Tm5 trigonal bipyramids.