DOE OSTI2020
BaHg2(OCl)2 crystallizes in the tetragonal P4/mbm space group. The structure is three-dimensional. Ba2+ is bonded in a 9-coordinate geometry to four equivalent O2- and five Cl1- atoms. All Ba–O bond lengths are 2.80 Å. There are a spread of Ba–Cl bond distances ranging from 3.20–3.77 Å. Hg2+ is bonded in a distorted linear geometry to two equivalent O2- and four Cl1- atoms. There are one shorter (2.10 Å) and one longer (2.11 Å) Hg–O bond lengths. There are two shorter (3.10 Å) and two longer (3.17 Å) Hg–Cl bond lengths. O2- is bonded to two equivalent Ba2+ and two equivalent Hg2+ atoms to form a mixture of distorted edge and corner-sharing OBa2Hg2 tetrahedra. There are three inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded in a distorted square co-planar geometry to four equivalent Ba2+ atoms. In the second Cl1- site, Cl1- is bonded in a 5-coordinate geometry to three equivalent Ba2+ and four equivalent Hg2+ atoms. In the third Cl1- site, Cl1- is bonded in a body-centered cubic geometry to eight equivalent Hg2+ atoms.