Materials Data on TlHg6Se4Br5 by Materials Project

Hg6TlSe4Br5 crystallizes in the tetragonal I4/m space group. The structure is three-dimensional. there are two inequivalent Hg2+ sites. In the first Hg2+ site, Hg2+ is bonded to two equivalent Se2- and four Br1- atoms to form a mixture of distorted edge, face, and corner-sharing HgSe2Br4 octahedra. The corner-sharing octahedra tilt angles range from 0–67°. There are one shorter (2.56 Å) and one longer (2.57 Å) Hg–Se bond lengths. There are a spread of Hg–Br bond distances ranging from 3.16–3.60 Å. In the second Hg2+ site, Hg2+ is bonded in a 4-coordinate geometry to two equivalent Se2- and two Br1- atoms. Both Hg–Se bond lengths are 2.57 Å. There are one shorter (2.88 Å) and one longer (3.22 Å) Hg–Br bond lengths. Tl1+ is bonded in a body-centered cubic geometry to eight Br1- atoms. There are four shorter (3.55 Å) and four longer (3.74 Å) Tl–Br bond lengths. Se2- is bonded in a 3-coordinate geometry to three Hg2+ atoms. There are four inequivalent Br1- sites. In the first Br1- site, Br1- is bonded in a body-centered cubic geometry to eight equivalent Hg2+ atoms. In the second Br1- site, Br1- is bonded in a body-centered cubic geometry to eight equivalent Hg2+ atoms. In the third Br1- site, Br1- is bonded in a 5-coordinate geometry to three Hg2+ and two equivalent Tl1+ atoms. In the fourth Br1- site, Br1- is bonded in a 5-coordinate geometry to three Hg2+ and two equivalent Tl1+ atoms.