Tl3SbSe3 crystallizes in the cubic P2_13 space group. There are three inequivalent Tl sites. In the first Tl site, Tl(1) is bonded in a distorted T-shaped geometry to three equivalent Se(1) atoms. In the second Tl site, Tl(2) is bonded in a distorted T-shaped geometry to three equivalent Se(1) atoms. In the third Tl site, Tl(3) is bonded in a distorted T-shaped geometry to three equivalent Se(1) atoms. Sb(1) is bonded in a trigonal non-coplanar geometry to three equivalent Se(1) atoms. Se(1) is bonded to one Tl(1), one Tl(2), one Tl(3), and one Sb(1) atom to form a mixture of distorted corner and edge-sharing SeTl3Sb trigonal pyramids.
Tl3SbSe3 crystallizes in the cubic P2_13 space group. There are three inequivalent Tl sites. In the first Tl site, Tl(1) is bonded in a distorted T-shaped geometry to three equivalent Se(1) atoms. All Tl(1)-Se(1) bond lengths are 3.21 Å. In the second Tl site, Tl(2) is bonded in a distorted T-shaped geometry to three equivalent Se(1) atoms. All Tl(2)-Se(1) bond lengths are 3.18 Å. In the third Tl site, Tl(3) is bonded in a distorted T-shaped geometry to three equivalent Se(1) atoms. All Tl(3)-Se(1) bond lengths are 3.16 Å. Sb(1) is bonded in a trigonal non-coplanar geometry to three equivalent Se(1) atoms. All Sb(1)-Se(1) bond lengths are 2.59 Å. Se(1) is bonded to one Tl(1), one Tl(2), one Tl(3), and one Sb(1) atom to form a mixture of distorted corner and edge-sharing SeTl3Sb trigonal pyramids.