DOI: 10.17188/1276122
title: Materials Data on Hg3Te2IBr by Materials Project

description: Hg3Te2BrI crystallizes in the monoclinic C2 space group. The structure is three-dimensional. there are seven inequivalent Hg2+ sites. In the first Hg2+ site, Hg2+ is bonded to two Te2-, one I1-, and two Br1- atoms to form a mixture of distorted edge and corner-sharing HgTe2IBr2 square pyramids. The corner-sharing octahedra tilt angles range from 59–62°. Both Hg–Te bond lengths are 2.75 Å. The Hg–I bond length is 3.41 Å. There are one shorter (3.03 Å) and one longer (3.58 Å) Hg–Br bond lengths. In the second Hg2+ site, Hg2+ is bonded to two equivalent Te2-, two equivalent I1-, and two equivalent Br1- atoms to form distorted HgTe2I2Br2 octahedra that share corners with four equivalent HgTe2I2Br2 octahedra, edges with four HgTe2I2Br2 octahedra, edges with two equivalent HgTe2IBr2 square pyramids, and faces with two equivalent HgTe2I4 octahedra. The corner-sharing octahedra tilt angles range from 11–14°. Both Hg–Te bond lengths are 2.75 Å. Both Hg–I bond lengths are 3.74 Å. Both Hg–Br bond lengths are 3.16 Å. In the third Hg2+ site, Hg2+ is bonded to two Te2-, two equivalent I1-, and two equivalent Br1- atoms to form HgTe2I2Br2 octahedra that share corners with eight HgTe2I2Br2 octahedra, a cornercorner with one HgTe2IBr2 square pyramid, edges with four HgTe2I2Br2 octahedra, and an edgeedge with one HgTe2IBr2 square pyramid. The corner-sharing octahedra tilt angles range from 8–73°. There are one shorter (2.74 Å) and one longer (2.75 Å) Hg–Te bond lengths. There are one shorter (3.29 Å) and one longer (3.67 Å) Hg–I bond lengths. There are one shorter (3.30 Å) and one longer (3.51 Å) Hg–Br bond lengths. In the fourth Hg2+ site, Hg2+ is bonded to two Te2- and four I1- atoms to form distorted HgTe2I4 octahedra that share corners with four equivalent HgTe2I2Br2 octahedra, a cornercorner with one HgTe2IBr2 square pyramid, edges with two equivalent HgTe2I4 octahedra, an edgeedge with one HgTe2IBr2 square pyramid, and faces with two HgTe2I2Br2 octahedra. The corner-sharing octahedra tilt angles range from 55–73°. Both Hg–Te bond lengths are 2.74 Å. There are a spread of Hg–I bond distances ranging from 3.33–3.85 Å. In the fifth Hg2+ site, Hg2+ is bonded to two equivalent Te2-, two equivalent I1-, and two equivalent Br1- atoms to form HgTe2I2Br2 octahedra that share corners with four equivalent HgTe2I2Br2 octahedra, corners with two equivalent HgTe2IBr2 square pyramids, edges with four HgTe2I2Br2 octahedra, and faces with two equivalent HgTe2I4 octahedra. The corner-sharing octahedra tilt angles range from 8–9°. Both Hg–Te bond lengths are 2.74 Å. Both Hg–I bond lengths are 3.36 Å. Both Hg–Br bond lengths are 3.56 Å. In the sixth Hg2+ site, Hg2+ is bonded in a 4-coordinate geometry to two Te2-, one I1-, and one Br1- atom. There are one shorter (2.76 Å) and one longer (2.77 Å) Hg–Te bond lengths. The Hg–I bond length is 3.42 Å. The Hg–Br bond length is 2.92 Å. In the seventh Hg2+ site, Hg2+ is bonded in a distorted rectangular see-saw-like geometry to two Te2-, one I1-, and one Br1- atom. Both Hg–Te bond lengths are 2.74 Å. The Hg–I bond length is 3.44 Å. The Hg–Br bond length is 3.07 Å. There are four inequivalent Te2- sites. In the first Te2- site, Te2- is bonded in a 3-coordinate geometry to three Hg2+ atoms. In the second Te2- site, Te2- is bonded in a 4-coordinate geometry to three Hg2+ atoms. In the third Te2- site, Te2- is bonded in a 4-coordinate geometry to three Hg2+ and one Br1- atom. The Te–Br bond length is 4.10 Å. In the fourth Te2- site, Te2- is bonded in a 4-coordinate geometry to three Hg2+ and one Br1- atom. The Te–Br bond length is 4.12 Å. There are two inequivalent I1- sites. In the first I1- site, I1- is bonded in a 7-coordinate geometry to five Hg2+ atoms. In the second I1- site, I1- is bonded in a 2-coordinate geometry to six Hg2+ atoms. There are two inequivalent Br1- sites. In the first Br1- site, Br1- is bonded in a 3-coordinate geometry to three Hg2+ and two Te2- atoms. In the second Br1- site, Br1- is bonded in a 5-coordinate geometry to five Hg2+ atoms.