Materials Data on FeHg2O3F5 by Materials Project
(FeHg2O2F5)2O2 crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional and consists of two water molecules and one FeHg2O2F5 framework. In the FeHg2O2F5 framework, Fe is bonded to six F atoms to form FeF6 octahedra that share corners with two equivalent FeF6 octahedra and corners with eight equivalent HgO2F4 octahedra. The corner-sharing octahedra tilt angles range from 2–56°. There are a spread of Fe–F bond distances ranging from 1.93–1.99 Å. Hg is bonded to two O and four F atoms to form distorted HgO2F4 octahedra that share corners with two equivalent HgO2F4 octahedra, corners with four equivalent FeF6 octahedra, and edges with two equivalent HgO2F4 octahedra. The corner-sharing octahedra tilt angles range from 55–57°. Both Hg–O bond lengths are 2.11 Å. All Hg–F bond lengths are 2.56 Å. There are two inequivalent O sites. In the first O site, O is bonded in a bent 120 degrees geometry to two equivalent Hg atoms. In the second O site, O is bonded in a bent 120 degrees geometry to two equivalent Hg atoms. There are three inequivalent F sites. In the first F site, F is bonded in a distorted single-bond geometry to one Fe and two equivalent Hg atoms. In the second F site, F is bonded in a distorted single-bond geometry to one Fe and two equivalent Hg atoms. In the third F site, F is bonded in a linear geometry to two equivalent Fe atoms.