Materials Data on Li2FeO2F by Materials Project

Abstract

Li2FeO2F is beta Polonium-derived structured and crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. there are four 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 LiO4F2 octahedra, corners with four equivalent FeO4F2 octahedra, edges with four equivalent FeO4F2 octahedra, and edges with eight LiO4F2 octahedra. The corner-sharing octahedra tilt angles range from 3–12°. There are two shorter (2.05 Å) and two longer (2.18 Å) Li–O bond lengths. Both Li–F bond lengths are 2.20 Å. In the second Li1+ site, Li1+ is bonded to four O2- and two equivalent F1- atoms to form LiO4F2 octahedra that share corners with two equivalent LiO4F2 octahedra, corners with four equivalent FeO4F2 octahedra, edges with four equivalent FeO4F2 octahedra, and edges with eight LiO4F2 octahedra. The corner-sharing octahedra tilt angles range from 6–8°. There are two shorter (2.09 Å) and two longer (2.10 Å) Li–O bond lengths. Both Li–F bond lengths are 2.31 Å. In the third Li1+ site, Li1+ is bonded to four O2- and two equivalent F1- atoms to form LiO4F2 octahedra that share corners with two equivalent LiO4F2 octahedra, corners with four equivalent FeO4F2 octahedra, edges with four equivalent FeO4F2 octahedra, and edges with eight LiO4F2 octahedra. The corner-sharing octahedra tilt angles range from 2–8°. There are two shorter (2.14 Å) and two longer (2.18 Å) Li–O bond lengths. Both Li–F bond lengths are 2.19 Å. In the fourth Li1+ site, Li1+ is bonded to four O2- and two equivalent F1- atoms to form LiO4F2 octahedra that share corners with six LiO4F2 octahedra, edges with six LiO4F2 octahedra, and edges with six equivalent FeO4F2 octahedra. The corner-sharing octahedra tilt angles range from 3–6°. There are two shorter (2.14 Å) and two longer (2.16 Å) Li–O bond lengths. Both Li–F bond lengths are 2.13 Å. Fe3+ is bonded to four O2- and two equivalent F1- atoms to form FeO4F2 octahedra that share corners with six LiO4F2 octahedra, edges with three equivalent FeO4F2 octahedra, and edges with nine LiO4F2 octahedra. The corner-sharing octahedra tilt angles range from 2–12°. There are a spread of Fe–O bond distances ranging from 1.96–2.01 Å. There are one shorter (2.19 Å) and one longer (2.21 Å) Fe–F bond lengths. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded to four Li1+ and two equivalent Fe3+ atoms to form OLi4Fe2 octahedra that share corners with two equivalent FLi4Fe2 octahedra, corners with four OLi4Fe2 octahedra, edges with five equivalent FLi4Fe2 octahedra, and edges with seven OLi4Fe2 octahedra. The corner-sharing octahedra tilt angles range from 0–13°. 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 FLi4Fe2 octahedra, corners with four OLi4Fe2 octahedra, edges with five equivalent FLi4Fe2 octahedra, and edges with seven OLi4Fe2 octahedra. The corner-sharing octahedra tilt angles range from 0–10°. F1- is bonded to four Li1+ and two equivalent Fe3+ atoms to form FLi4Fe2 octahedra that share corners with two equivalent FLi4Fe2 octahedra, corners with four OLi4Fe2 octahedra, edges with two equivalent FLi4Fe2 octahedra, and edges with ten OLi4Fe2 octahedra. The corner-sharing octahedra tilt angles range from 0–10°.