TlSbSe2 crystallizes in the orthorhombic Pmm2 space group. Tl(1) is bonded to two equivalent Sb(1) and four equivalent Se(1) atoms to form a mixture of corner and edge-sharing TlSb2Se4 octahedra. The corner-sharing octahedral tilt angles range from 3-16°. Sb(1) is bonded in a distorted see-saw-like geometry to two equivalent Tl(1) and two equivalent Se(2) atoms. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded in a distorted rectangular see-saw-like geometry to four equivalent Tl(1) atoms. In the second Se site, Se(2) is bonded in a distorted water-like geometry to two equivalent Sb(1) atoms.
TlSbSe2 crystallizes in the orthorhombic Pmm2 space group. Tl(1) is bonded to two equivalent Sb(1) and four equivalent Se(1) atoms to form a mixture of corner and edge-sharing TlSb2Se4 octahedra. The corner-sharing octahedral tilt angles range from 3-16°. Both Tl(1)-Sb(1) bond lengths are 3.01 Å. There are two shorter (3.00 Å) and two longer (3.15 Å) Tl(1)-Se(1) bond lengths. Sb(1) is bonded in a distorted see-saw-like geometry to two equivalent Tl(1) and two equivalent Se(2) atoms. Both Sb(1)-Se(2) bond lengths are 2.77 Å. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded in a distorted rectangular see-saw-like geometry to four equivalent Tl(1) atoms. In the second Se site, Se(2) is bonded in a distorted water-like geometry to two equivalent Sb(1) atoms.