Materials Data on Li2FeO2F by Materials Project

Abstract

Li2FeO2F is Caswellsilverite-derived structured and crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are two inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded to four O2- and two equivalent F1- atoms to form LiO4F2 octahedra that share corners with two equivalent FeO5F octahedra, corners with four LiO4F2 octahedra, edges with five equivalent FeO5F octahedra, and edges with seven LiO4F2 octahedra. The corner-sharing octahedra tilt angles range from 1–6°. There are a spread of Li–O bond distances ranging from 2.05–2.16 Å. There are one shorter (2.10 Å) and one longer (2.21 Å) Li–F bond lengths. In the second Li1+ site, Li1+ is bonded to three O2- and three equivalent F1- atoms to form LiO3F3 octahedra that share corners with six LiO4F2 octahedra, edges with five equivalent FeO5F octahedra, and edges with seven LiO4F2 octahedra. The corner-sharing octahedra tilt angles range from 3–6°. There are a spread of Li–O bond distances ranging from 2.09–2.17 Å. There are one shorter (1.99 Å) and two longer (2.06 Å) Li–F bond lengths. Fe3+ is bonded to five O2- and one F1- atom to form FeO5F octahedra that share corners with two equivalent LiO4F2 octahedra, corners with four equivalent FeO5F octahedra, edges with two equivalent FeO5F octahedra, and edges with ten LiO4F2 octahedra. The corner-sharing octahedra tilt angles range from 1–13°. There are a spread of Fe–O bond distances ranging from 1.97–2.07 Å. The Fe–F bond length is 2.25 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded to three Li1+ and three equivalent Fe3+ atoms to form OLi3Fe3 octahedra that share corners with six OLi3Fe3 octahedra, edges with five equivalent FLi5Fe octahedra, and edges with seven OLi3Fe3 octahedra. The corner-sharing octahedra tilt angles range from 1–13°. In the second O2- site, O2- is bonded to four Li1+ and two equivalent Fe3+ atoms to form OLi4Fe2 octahedra that share corners with two equivalent FLi5Fe octahedra, corners with four OLi3Fe3 octahedra, edges with five equivalent FLi5Fe octahedra, and edges with seven OLi3Fe3 octahedra. The corner-sharing octahedra tilt angles range from 1–12°. F1- is bonded to five Li1+ and one Fe3+ atom to form FLi5Fe octahedra that share corners with two equivalent OLi4Fe2 octahedra, corners with four equivalent FLi5Fe octahedra, edges with two equivalent FLi5Fe octahedra, and edges with ten OLi3Fe3 octahedra. The corner-sharing octahedra tilt angles range from 1–5°.