TmCuPbS3 crystallizes in the orthorhombic Cmc2_1 space group. Tm(1) is bonded to two equivalent S(1), two equivalent S(2), and two equivalent S(3) atoms to form TmS6 octahedra that share corners with two equivalent Tm(1)S6 octahedra, edges with two equivalent Tm(1)S6 octahedra, and edges with four equivalent Cu(1)S4 tetrahedra. The corner-sharing octahedral tilt angles are 41°. Cu(1) is bonded to one S(2), one S(3), and two equivalent S(1) atoms to form CuS4 tetrahedra that share corners with two equivalent Cu(1)S4 tetrahedra and edges with four equivalent Tm(1)S6 octahedra. Pb(1) is bonded in a 4-coordinate geometry to two equivalent S(1) and two equivalent S(3) atoms. There are three inequivalent S sites. In the first S site, S(1) is bonded in a 6-coordinate geometry to two equivalent Tm(1), two equivalent Cu(1), and two equivalent Pb(1) atoms. In the second S site, S(2) is bonded in a 3-coordinate geometry to two equivalent Tm(1) and one Cu(1) atom. In the third S site, S(3) is bonded in a 5-coordinate geometry to two equivalent Tm(1), one Cu(1), and two equivalent Pb(1) atoms.
TmCuPbS3 crystallizes in the orthorhombic Cmc2_1 space group. Tm(1) is bonded to two equivalent S(1), two equivalent S(2), and two equivalent S(3) atoms to form TmS6 octahedra that share corners with two equivalent Tm(1)S6 octahedra, edges with two equivalent Tm(1)S6 octahedra, and edges with four equivalent Cu(1)S4 tetrahedra. The corner-sharing octahedral tilt angles are 41°. Both Tm(1)-S(1) bond lengths are 2.71 Å. Both Tm(1)-S(2) bond lengths are 2.70 Å. Both Tm(1)-S(3) bond lengths are 2.75 Å. Cu(1) is bonded to one S(2), one S(3), and two equivalent S(1) atoms to form CuS4 tetrahedra that share corners with two equivalent Cu(1)S4 tetrahedra and edges with four equivalent Tm(1)S6 octahedra. The Cu(1)-S(2) bond length is 2.34 Å. The Cu(1)-S(3) bond length is 2.32 Å. Both Cu(1)-S(1) bond lengths are 2.40 Å. Pb(1) is bonded in a 4-coordinate geometry to two equivalent S(1) and two equivalent S(3) atoms. Both Pb(1)-S(1) bond lengths are 3.05 Å. Both Pb(1)-S(3) bond lengths are 2.96 Å. There are three inequivalent S sites. In the first S site, S(1) is bonded in a 6-coordinate geometry to two equivalent Tm(1), two equivalent Cu(1), and two equivalent Pb(1) atoms. In the second S site, S(2) is bonded in a 3-coordinate geometry to two equivalent Tm(1) and one Cu(1) atom. In the third S site, S(3) is bonded in a 5-coordinate geometry to two equivalent Tm(1), one Cu(1), and two equivalent Pb(1) atoms.