Tl2(ReSe2)3 crystallizes in the monoclinic C2/c space group. There are three inequivalent Re sites. In the first Re site, Re(1) is bonded to one Se(1), one Se(2), one Se(3), one Se(4), and one Se(5) atom to form a mixture of distorted corner and edge-sharing ReSe5 square pyramids. In the second Re site, Re(2) is bonded to one Se(1), one Se(2), one Se(3), one Se(4), and one Se(5) atom to form a mixture of distorted corner and edge-sharing ReSe5 square pyramids. In the third Re site, Re(3) is bonded to one Se(1), one Se(2), one Se(3), one Se(4), and one Se(6) atom to form distorted edge-sharing ReSe5 square pyramids. There are three inequivalent Tl sites. In the first Tl site, Tl(1) is bonded in a 3-coordinate geometry to one Se(5), one Se(6), and two equivalent Se(2) atoms. In the second Tl site, Tl(2) is bonded in a 6-coordinate geometry to two equivalent Se(1), two equivalent Se(5), and two equivalent Se(6) atoms. In the third Tl site, Tl(3) is bonded in a bent 120 degrees geometry to two equivalent Se(5) atoms. There are six inequivalent Se sites. In the first Se site, Se(1) is bonded in a 4-coordinate geometry to one Re(1), one Re(2), one Re(3), and one Tl(2) atom. In the second Se site, Se(2) is bonded in a 5-coordinate geometry to one Re(1), one Re(2), one Re(3), and two equivalent Tl(1) atoms. In the third Se site, Se(3) is bonded in a 3-coordinate geometry to one Re(1), one Re(2), and one Re(3) atom. In the fourth Se site, Se(4) is bonded in a 3-coordinate geometry to one Re(1), one Re(2), and one Re(3) atom. In the fifth Se site, Se(5) is bonded in a 5-coordinate geometry to one Re(1), one Re(2), one Tl(1), one Tl(2), and one Tl(3) atom. In the sixth Se site, Se(6) is bonded in a 4-coordinate geometry to one Re(3), one Tl(1), one Tl(2), and one Se(6) atom.
Tl2(ReSe2)3 crystallizes in the monoclinic C2/c space group. There are three inequivalent Re sites. In the first Re site, Re(1) is bonded to one Se(1), one Se(2), one Se(3), one Se(4), and one Se(5) atom to form a mixture of distorted corner and edge-sharing ReSe5 square pyramids. The Re(1)-Se(1) bond length is 2.54 Å. The Re(1)-Se(2) bond length is 2.54 Å. The Re(1)-Se(3) bond length is 2.52 Å. The Re(1)-Se(4) bond length is 2.56 Å. The Re(1)-Se(5) bond length is 2.64 Å. In the second Re site, Re(2) is bonded to one Se(1), one Se(2), one Se(3), one Se(4), and one Se(5) atom to form a mixture of distorted corner and edge-sharing ReSe5 square pyramids. The Re(2)-Se(1) bond length is 2.52 Å. The Re(2)-Se(2) bond length is 2.54 Å. The Re(2)-Se(3) bond length is 2.53 Å. The Re(2)-Se(4) bond length is 2.56 Å. The Re(2)-Se(5) bond length is 2.65 Å. In the third Re site, Re(3) is bonded to one Se(1), one Se(2), one Se(3), one Se(4), and one Se(6) atom to form distorted edge-sharing ReSe5 square pyramids. The Re(3)-Se(1) bond length is 2.52 Å. The Re(3)-Se(2) bond length is 2.55 Å. The Re(3)-Se(3) bond length is 2.53 Å. The Re(3)-Se(4) bond length is 2.57 Å. The Re(3)-Se(6) bond length is 2.61 Å. There are three inequivalent Tl sites. In the first Tl site, Tl(1) is bonded in a 3-coordinate geometry to one Se(5), one Se(6), and two equivalent Se(2) atoms. The Tl(1)-Se(5) bond length is 3.13 Å. The Tl(1)-Se(6) bond length is 3.21 Å. There is one shorter (3.28 Å) and one longer (3.39 Å) Tl(1)-Se(2) bond length. In the second Tl site, Tl(2) is bonded in a 6-coordinate geometry to two equivalent Se(1), two equivalent Se(5), and two equivalent Se(6) atoms. Both Tl(2)-Se(1) bond lengths are 3.22 Å. Both Tl(2)-Se(5) bond lengths are 3.33 Å. Both Tl(2)-Se(6) bond lengths are 3.27 Å. In the third Tl site, Tl(3) is bonded in a bent 120 degrees geometry to two equivalent Se(5) atoms. Both Tl(3)-Se(5) bond lengths are 3.15 Å. There are six inequivalent Se sites. In the first Se site, Se(1) is bonded in a 4-coordinate geometry to one Re(1), one Re(2), one Re(3), and one Tl(2) atom. In the second Se site, Se(2) is bonded in a 5-coordinate geometry to one Re(1), one Re(2), one Re(3), and two equivalent Tl(1) atoms. In the third Se site, Se(3) is bonded in a 3-coordinate geometry to one Re(1), one Re(2), and one Re(3) atom. In the fourth Se site, Se(4) is bonded in a 3-coordinate geometry to one Re(1), one Re(2), and one Re(3) atom. In the fifth Se site, Se(5) is bonded in a 5-coordinate geometry to one Re(1), one Re(2), one Tl(1), one Tl(2), and one Tl(3) atom. In the sixth Se site, Se(6) is bonded in a 4-coordinate geometry to one Re(3), one Tl(1), one Tl(2), and one Se(6) atom. The Se(6)-Se(6) bond length is 2.42 Å.