KTlSe2 crystallizes in the tetragonal I4/mcm space group. K(1) is bonded in a 8-coordinate geometry to eight equivalent Se(1) atoms. Tl(1) is bonded to four equivalent Se(1) atoms to form edge-sharing TlSe4 tetrahedra. Se(1) is bonded in a 6-coordinate geometry to four equivalent K(1) and two equivalent Tl(1) atoms.
KTlSe2 crystallizes in the tetragonal I4/mcm space group. K(1) is bonded in a 8-coordinate geometry to eight equivalent Se(1) atoms. All K(1)-Se(1) bond lengths are 3.49 Å. Tl(1) is bonded to four equivalent Se(1) atoms to form edge-sharing TlSe4 tetrahedra. All Tl(1)-Se(1) bond lengths are 2.70 Å. Se(1) is bonded in a 6-coordinate geometry to four equivalent K(1) and two equivalent Tl(1) atoms.