Materials Data on Cr2Hg2H2O9 by Materials Project
Cr2Hg2H2O9 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. Cr6+ is bonded in a tetrahedral geometry to four O2- atoms. There are a spread of Cr–O bond distances ranging from 1.62–1.74 Å. Hg2+ is bonded in a 2-coordinate geometry to seven O2- atoms. There are a spread of Hg–O bond distances ranging from 2.10–2.80 Å. H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to one Cr6+ and two equivalent Hg2+ atoms. In the second O2- site, O2- is bonded in a single-bond geometry to one Cr6+ and one Hg2+ atom. In the third O2- site, O2- is bonded in a water-like geometry to two equivalent Hg2+ and two equivalent H1+ atoms. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to one Cr6+ and two equivalent Hg2+ atoms. In the fifth O2- site, O2- is bonded in a single-bond geometry to one Cr6+ and one Hg2+ atom.