DOE OSTI2020
HgHgBrHg4O3BrHg2OBr crystallizes in the monoclinic P2_1/c space group. The structure is two-dimensional and consists of four mercury molecules; four Hg2OBr clusters; two HgBr ribbons oriented in the (0, 1, 0) direction; and two Hg4O3Br sheets oriented in the (0, 0, 1) direction. In each Hg2OBr cluster, there are two inequivalent Hg+1.38+ sites. In the first Hg+1.38+ site, Hg+1.38+ is bonded in a 1-coordinate geometry to one Br1- atom. The Hg–Br bond length is 3.10 Å. In the second Hg+1.38+ site, Hg+1.38+ is bonded in a single-bond geometry to one O2- atom. The Hg–O bond length is 2.29 Å. O2- is bonded in a bent 120 degrees geometry to one Hg+1.38+ and one Br1- atom. The O–Br bond length is 1.79 Å. Br1- is bonded in a distorted L-shaped geometry to one Hg+1.38+ and one O2- atom. In each HgBr ribbon, Hg+1.38+ is bonded in a 2-coordinate geometry to one Hg+1.38+ and two equivalent Br1- atoms. The Hg–Hg bond length is 2.63 Å. There are one shorter (2.55 Å) and one longer (3.14 Å) Hg–Br bond lengths. Br1- is bonded in an L-shaped geometry to two equivalent Hg+1.38+ atoms. In each Hg4O3Br sheet, there are four inequivalent Hg+1.38+ sites. In the first Hg+1.38+ site, Hg+1.38+ is bonded in a distorted linear geometry to two O2- and three equivalent Br1- atoms. Both Hg–O bond lengths are 2.11 Å. There are a spread of Hg–Br bond distances ranging from 3.21–3.27 Å. In the second Hg+1.38+ site, Hg+1.38+ is bonded in a 2-coordinate geometry to two O2- and one Br1- atom. Both Hg–O bond lengths are 2.47 Å. The Hg–Br bond length is 3.02 Å. In the third Hg+1.38+ site, Hg+1.38+ is bonded in a distorted single-bond geometry to one O2- atom. The Hg–O bond length is 2.90 Å. In the fourth Hg+1.38+ site, Hg+1.38+ is bonded to three O2- and one Br1- atom to form distorted corner-sharing HgBrO3 trigonal pyramids. There are a spread of Hg–O bond distances ranging from 2.29–2.34 Å. The Hg–Br bond length is 2.92 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded to four Hg+1.38+ atoms to form corner-sharing OHg4 tetrahedra. In the second O2- site, O2- is bonded in a distorted water-like geometry to one Hg+1.38+ and one O2- atom. The O–O bond length is 1.40 Å. In the third O2- site, O2- is bonded in a 4-coordinate geometry to three Hg+1.38+ and one O2- atom. Br1- is bonded in a 5-coordinate geometry to five Hg+1.38+ atoms.