DOI: 10.17188/1319392
title: Materials Data on FeO2 by Materials Project

description: FeO2 crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are eight inequivalent Fe sites. In the first Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share corners with three FeO4 tetrahedra and edges with four equivalent FeO6 octahedra. There are a spread of Fe–O bond distances ranging from 1.88–2.09 Å. In the second Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share corners with three FeO4 tetrahedra and edges with four FeO6 octahedra. There are a spread of Fe–O bond distances ranging from 1.88–2.09 Å. In the third Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share a cornercorner with one FeO4 tetrahedra and edges with five FeO6 octahedra. There are a spread of Fe–O bond distances ranging from 1.85–2.12 Å. In the fourth Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share a cornercorner with one FeO4 tetrahedra and edges with five FeO6 octahedra. There are a spread of Fe–O bond distances ranging from 1.86–2.12 Å. In the fifth Fe site, Fe is bonded to six O atoms to form edge-sharing FeO6 octahedra. There is three shorter (1.88 Å) and three longer (1.95 Å) Fe–O bond length. In the sixth Fe site, Fe is bonded to four O atoms to form corner-sharing FeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 57–58°. There is three shorter (1.92 Å) and one longer (1.95 Å) Fe–O bond length. In the seventh Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share corners with two equivalent FeO4 tetrahedra and edges with five FeO6 octahedra. There are a spread of Fe–O bond distances ranging from 1.97–2.05 Å. In the eighth Fe site, Fe is bonded to four O atoms to form corner-sharing FeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 53–58°. There is three shorter (1.88 Å) and one longer (1.93 Å) Fe–O bond length. There are eighteen inequivalent O sites. In the first O site, O is bonded in a water-like geometry to two equivalent Fe atoms. In the second O site, O is bonded in a distorted T-shaped geometry to three Fe atoms. In the third O site, O is bonded in a water-like geometry to two Fe atoms. In the fourth O site, O is bonded in a water-like geometry to two equivalent Fe atoms. In the fifth O site, O is bonded in a trigonal planar geometry to three Fe atoms. In the sixth O site, O is bonded in a distorted T-shaped geometry to three Fe atoms. In the seventh O site, O is bonded in a distorted trigonal pyramidal geometry to four Fe atoms. In the eighth O site, O is bonded in a water-like geometry to two Fe atoms. In the ninth O site, O is bonded in a trigonal planar geometry to three Fe atoms. In the tenth O site, O is bonded in a distorted T-shaped geometry to three Fe atoms. Both O–Fe bond lengths are 2.05 Å. In the eleventh O site, O is bonded in a distorted trigonal non-coplanar geometry to three Fe atoms. In the twelfth O site, O is bonded in a distorted trigonal non-coplanar geometry to three equivalent Fe atoms. In the thirteenth O site, O is bonded in a distorted rectangular see-saw-like geometry to four Fe atoms. In the fourteenth O site, O is bonded in a distorted T-shaped geometry to three Fe atoms. In the fifteenth O site, O is bonded in a distorted trigonal non-coplanar geometry to three Fe atoms. In the sixteenth O site, O is bonded in a trigonal planar geometry to three Fe atoms. In the seventeenth O site, O is bonded in a distorted trigonal non-coplanar geometry to three equivalent Fe atoms. In the eighteenth O site, O is bonded in a trigonal planar geometry to three Fe atoms. Both O–Fe bond lengths are 1.98 Å.