DOE OSTI2020
Fe3(O2F)2 is Hydrophilite-derived structured and crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are six inequivalent Fe sites. In the first Fe site, Fe is bonded to four O and two F atoms to form FeO4F2 octahedra that share corners with eight FeO4F2 octahedra and edges with two FeO5F octahedra. The corner-sharing octahedra tilt angles range from 44–52°. There are a spread of Fe–O bond distances ranging from 1.91–1.95 Å. There are one shorter (2.05 Å) and one longer (2.09 Å) Fe–F bond lengths. In the second Fe site, Fe is bonded to five O and one F atom to form a mixture of corner and edge-sharing FeO5F octahedra. The corner-sharing octahedra tilt angles range from 46–57°. There are a spread of Fe–O bond distances ranging from 1.96–2.10 Å. The Fe–F bond length is 2.10 Å. In the third Fe site, Fe is bonded to four O and two F atoms to form a mixture of corner and edge-sharing FeO4F2 octahedra. The corner-sharing octahedra tilt angles range from 45–57°. There are a spread of Fe–O bond distances ranging from 1.95–2.00 Å. There are one shorter (2.12 Å) and one longer (2.21 Å) Fe–F bond lengths. In the fourth Fe site, Fe is bonded to four O and two F atoms to form a mixture of corner and edge-sharing FeO4F2 octahedra. The corner-sharing octahedra tilt angles range from 45–54°. There are a spread of Fe–O bond distances ranging from 1.93–1.98 Å. There are one shorter (2.05 Å) and one longer (2.06 Å) Fe–F bond lengths. In the fifth Fe site, Fe is bonded to four O and two F atoms to form a mixture of corner and edge-sharing FeO4F2 octahedra. The corner-sharing octahedra tilt angles range from 44–57°. There are a spread of Fe–O bond distances ranging from 1.91–2.03 Å. There are one shorter (2.12 Å) and one longer (2.18 Å) Fe–F bond lengths. In the sixth Fe site, Fe is bonded to three O and three F atoms to form a mixture of corner and edge-sharing FeO3F3 octahedra. The corner-sharing octahedra tilt angles range from 46–57°. There is one shorter (1.92 Å) and two longer (1.98 Å) Fe–O bond length. There are a spread of Fe–F bond distances ranging from 2.01–2.07 Å. There are eight inequivalent O sites. In the first O site, O is bonded in a trigonal planar geometry to three Fe atoms. In the second O site, O is bonded in a trigonal planar geometry to three Fe atoms. In the third O site, O is bonded in a distorted trigonal planar geometry to three Fe atoms. In the fourth O site, O is bonded in a distorted trigonal planar geometry to three Fe atoms. In the fifth O site, O is bonded in a distorted trigonal planar geometry to three Fe atoms. In the sixth O site, O is bonded in a trigonal planar geometry to three Fe atoms. In the seventh O site, O is bonded in a trigonal planar geometry to three Fe atoms. In the eighth O site, O is bonded in a trigonal planar geometry to three Fe atoms. There are four inequivalent F sites. In the first F site, F is bonded in a distorted trigonal planar geometry to three Fe atoms. In the second F site, F is bonded in a distorted trigonal planar geometry to three Fe atoms. In the third F site, F is bonded in a distorted T-shaped geometry to three Fe atoms. In the fourth F site, F is bonded in a distorted trigonal planar geometry to three Fe atoms.