Tl4PbSe3 crystallizes in the tetragonal P4/ncc space group. Tl(1) is bonded in a 3-coordinate geometry to one Se(1) and two equivalent Se(2) atoms. Pb(1) is bonded to one Se(1) and four equivalent Se(2) atoms to form distorted corner-sharing PbSe5 square pyramids. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded in a 5-coordinate geometry to four equivalent Tl(1) and one Pb(1) atom. In the second Se site, Se(2) is bonded in a 6-coordinate geometry to four equivalent Tl(1) and two equivalent Pb(1) atoms.
Tl4PbSe3 crystallizes in the tetragonal P4/ncc space group. Tl(1) is bonded in a 3-coordinate geometry to one Se(1) and two equivalent Se(2) atoms. The Tl(1)-Se(1) bond length is 3.22 Å. There is one shorter (3.01 Å) and one longer (3.19 Å) Tl(1)-Se(2) bond length. Pb(1) is bonded to one Se(1) and four equivalent Se(2) atoms to form distorted corner-sharing PbSe5 square pyramids. The Pb(1)-Se(1) bond length is 2.82 Å. All Pb(1)-Se(2) bond lengths are 3.21 Å. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded in a 5-coordinate geometry to four equivalent Tl(1) and one Pb(1) atom. In the second Se site, Se(2) is bonded in a 6-coordinate geometry to four equivalent Tl(1) and two equivalent Pb(1) atoms.