DOE OSTI2020
MgHg2(O3Br2)2(Br)2 crystallizes in the monoclinic C2/c space group. The structure is one-dimensional and consists of eight hydrobromic acid molecules and four MgHg2(O3Br2)2 ribbons oriented in the (0, 1, 0) direction. In each MgHg2(O3Br2)2 ribbon, Mg2+ is bonded in an octahedral geometry to six O2- atoms. There are a spread of Mg–O bond distances ranging from 1.98–2.22 Å. Hg2+ is bonded in a distorted L-shaped geometry to two O2- atoms. There are one shorter (2.17 Å) and one longer (2.21 Å) Hg–O bond lengths. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Mg2+ and one Br1+ atom. The O–Br bond length is 1.75 Å. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to one Mg2+ and two equivalent Hg2+ atoms. In the third O2- site, O2- is bonded in a bent 120 degrees geometry to one Mg2+ and one Br1+ atom. The O–Br bond length is 1.75 Å. In the fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Mg2+ and two equivalent Hg2+ atoms. There are two inequivalent Br1+ sites. In the first Br1+ site, Br1+ is bonded in a single-bond geometry to one O2- atom. In the second Br1+ site, Br1+ is bonded in a single-bond geometry to one O2- atom.