DOI: 10.17188/1276176
title: Materials Data on CuHg3As2Br3 by Materials Project

description: CuHg3As2Br3 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. there are two inequivalent Cu1+ sites. In the first Cu1+ site, Cu1+ is bonded to four Br1- atoms to form CuBr4 tetrahedra that share corners with four HgAs2Br4 octahedra, corners with two equivalent CuBr4 tetrahedra, edges with four HgAs2Br4 octahedra, and an edgeedge with one HgAs2Br4 pentagonal pyramid. The corner-sharing octahedra tilt angles range from 50–53°. There are two shorter (2.40 Å) and two longer (2.67 Å) Cu–Br bond lengths. In the second Cu1+ site, Cu1+ is bonded to four Br1- atoms to form CuBr4 tetrahedra that share corners with four HgAs2Br4 octahedra, corners with two CuBr4 tetrahedra, edges with three HgAs2Br4 octahedra, and an edgeedge with one HgAs2Br4 pentagonal pyramid. The corner-sharing octahedra tilt angles range from 55–90°. There are a spread of Cu–Br bond distances ranging from 2.36–2.74 Å. There are six inequivalent Hg2+ sites. In the first Hg2+ site, Hg2+ is bonded in a 6-coordinate geometry to two As2- and four Br1- atoms. There are one shorter (2.59 Å) and one longer (2.60 Å) Hg–As bond lengths. There are a spread of Hg–Br bond distances ranging from 3.01–3.56 Å. In the second Hg2+ site, Hg2+ is bonded to two equivalent As2- and four Br1- atoms to form distorted HgAs2Br4 pentagonal pyramids that share corners with four HgAs2Br4 octahedra, corners with two equivalent AsHg3As tetrahedra, edges with four HgAs2Br4 octahedra, and edges with three CuBr4 tetrahedra. The corner-sharing octahedra tilt angles range from 78–79°. Both Hg–As bond lengths are 2.59 Å. There are two shorter (3.03 Å) and two longer (3.42 Å) Hg–Br bond lengths. In the third Hg2+ site, Hg2+ is bonded to two As2- and four Br1- atoms to form HgAs2Br4 octahedra that share corners with six HgAs2Br4 octahedra, a cornercorner with one HgAs2Br4 pentagonal pyramid, corners with two equivalent CuBr4 tetrahedra, corners with two AsHg3As tetrahedra, edges with two HgAs2Br4 octahedra, and edges with two CuBr4 tetrahedra. The corner-sharing octahedra tilt angles range from 0–91°. There are one shorter (2.59 Å) and one longer (2.60 Å) Hg–As bond lengths. There are a spread of Hg–Br bond distances ranging from 3.21–3.30 Å. In the fourth Hg2+ site, Hg2+ is bonded to two As2- and four Br1- atoms to form distorted HgAs2Br4 octahedra that share corners with six HgAs2Br4 octahedra, a cornercorner with one CuBr4 tetrahedra, corners with two AsHg3As tetrahedra, edges with two HgAs2Br4 octahedra, an edgeedge with one HgAs2Br4 pentagonal pyramid, and edges with two equivalent CuBr4 tetrahedra. The corner-sharing octahedra tilt angles range from 0–91°. Both Hg–As bond lengths are 2.58 Å. There are a spread of Hg–Br bond distances ranging from 3.20–3.56 Å. In the fifth Hg2+ site, Hg2+ is bonded to two equivalent As2- and four Br1- atoms to form HgAs2Br4 octahedra that share corners with six HgAs2Br4 octahedra, corners with two equivalent HgAs2Br4 pentagonal pyramids, corners with two equivalent CuBr4 tetrahedra, corners with two equivalent AsHg3As tetrahedra, edges with two equivalent HgAs2Br4 octahedra, and edges with two equivalent CuBr4 tetrahedra. The corner-sharing octahedra tilt angles range from 27–90°. Both Hg–As bond lengths are 2.59 Å. There are two shorter (3.26 Å) and two longer (3.28 Å) Hg–Br bond lengths. In the sixth Hg2+ site, Hg2+ is bonded to two equivalent As2- and four Br1- atoms to form HgAs2Br4 octahedra that share corners with six HgAs2Br4 octahedra, corners with two equivalent AsHg3As tetrahedra, corners with four CuBr4 tetrahedra, edges with two equivalent HgAs2Br4 octahedra, and edges with two equivalent HgAs2Br4 pentagonal pyramids. The corner-sharing octahedra tilt angles range from 32–90°. Both Hg–As bond lengths are 2.56 Å. There are two shorter (3.34 Å) and two longer (3.47 Å) Hg–Br bond lengths. There are three inequivalent As2- sites. In the first As2- site, As2- is bonded to three Hg2+ and one As2- atom to form AsHg3As tetrahedra that share a cornercorner with one BrCu2Hg4 octahedra, corners with two HgAs2Br4 octahedra, and corners with three AsHg3As tetrahedra. The corner-sharing octahedra tilt angles range from 70–81°. The As–As bond length is 2.46 Å. In the second As2- site, As2- is bonded to three Hg2+ and one As2- atom to form AsHg3As tetrahedra that share corners with two HgAs2Br4 octahedra, corners with three AsHg3As tetrahedra, and an edgeedge with one BrCu2Hg4 octahedra. The corner-sharing octahedra tilt angles range from 72–74°. The As–As bond length is 2.44 Å. In the third As2- site, As2- is bonded to three Hg2+ and one As2- atom to form AsHg3As tetrahedra that share a cornercorner with one BrCu2Hg4 octahedra, corners with two HgAs2Br4 octahedra, a cornercorner with one HgAs2Br4 pentagonal pyramid, and corners with three AsHg3As tetrahedra. The corner-sharing octahedra tilt angles range from 71–82°. There are five inequivalent Br1- sites. In the first Br1- site, Br1- is bonded in a 1-coordinate geometry to one Cu1+ and four Hg2+ atoms. In the second Br1- site, Br1- is bonded in a 1-coordinate geometry to one Cu1+ and four Hg2+ atoms. In the third Br1- site, Br1- is bonded in a 1-coordinate geometry to one Cu1+ and four Hg2+ atoms. In the fourth Br1- site, Br1- is bonded to two equivalent Cu1+ and four Hg2+ atoms to form BrCu2Hg4 octahedra that share corners with four AsHg3As tetrahedra and edges with two equivalent AsHg3As tetrahedra. In the fifth Br1- site, Br1- is bonded in a 6-coordinate geometry to two Cu1+ and four Hg2+ atoms.