Tl3Fe2S4 crystallizes in the orthorhombic Pnma space group. Fe(1) is bonded to one S(1), one S(3), and two equivalent S(2) atoms to form edge-sharing FeS4 tetrahedra. There are two inequivalent Tl sites. In the first Tl site, Tl(1) is bonded in a 3-coordinate geometry to one S(2) and two equivalent S(3) atoms. In the second Tl site, Tl(2) is bonded in a 6-coordinate geometry to two equivalent S(1) and four equivalent S(2) atoms. There are three inequivalent S sites. In the first S site, S(1) is bonded in a 3-coordinate geometry to two equivalent Fe(1) and two equivalent Tl(2) atoms. In the second S site, S(2) is bonded in a 2-coordinate geometry to two equivalent Fe(1), one Tl(1), and two equivalent Tl(2) atoms. In the third S site, S(3) is bonded in a 6-coordinate geometry to two equivalent Fe(1) and four equivalent Tl(1) atoms.
Tl3Fe2S4 crystallizes in the orthorhombic Pnma space group. Fe(1) is bonded to one S(1), one S(3), and two equivalent S(2) atoms to form edge-sharing FeS4 tetrahedra. The Fe(1)-S(1) bond length is 2.27 Å. The Fe(1)-S(3) bond length is 2.29 Å. Both Fe(1)-S(2) bond lengths are 2.26 Å. There are two inequivalent Tl sites. In the first Tl site, Tl(1) is bonded in a 3-coordinate geometry to one S(2) and two equivalent S(3) atoms. The Tl(1)-S(2) bond length is 3.16 Å. There is one shorter (3.13 Å) and one longer (3.14 Å) Tl(1)-S(3) bond length. In the second Tl site, Tl(2) is bonded in a 6-coordinate geometry to two equivalent S(1) and four equivalent S(2) atoms. There is one shorter (3.10 Å) and one longer (3.30 Å) Tl(2)-S(1) bond length. There are two shorter (3.20 Å) and two longer (3.24 Å) Tl(2)-S(2) bond lengths. There are three inequivalent S sites. In the first S site, S(1) is bonded in a 3-coordinate geometry to two equivalent Fe(1) and two equivalent Tl(2) atoms. In the second S site, S(2) is bonded in a 2-coordinate geometry to two equivalent Fe(1), one Tl(1), and two equivalent Tl(2) atoms. In the third S site, S(3) is bonded in a 6-coordinate geometry to two equivalent Fe(1) and four equivalent Tl(1) atoms.