Materials Data on Li2MnFe3O8 by Materials Project
Li2MnFe3O8 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Li1+ is bonded to six O2- atoms to form LiO6 octahedra that share corners with six equivalent FeO6 octahedra, edges with two equivalent LiO6 octahedra, edges with two equivalent MnO6 octahedra, and edges with four FeO6 octahedra. The corner-sharing octahedra tilt angles range from 10–13°. There are a spread of Li–O bond distances ranging from 2.16–2.18 Å. Mn7+ is bonded to six O2- atoms to form MnO6 octahedra that share edges with four equivalent LiO6 octahedra and edges with six FeO6 octahedra. There is two shorter (1.93 Å) and four longer (1.95 Å) Mn–O bond length. There are two inequivalent Fe+2.33+ sites. In the first Fe+2.33+ site, Fe+2.33+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with six equivalent LiO6 octahedra, edges with two equivalent LiO6 octahedra, edges with two equivalent MnO6 octahedra, and edges with four FeO6 octahedra. The corner-sharing octahedra tilt angles range from 10–13°. There are a spread of Fe–O bond distances ranging from 2.03–2.07 Å. In the second Fe+2.33+ site, Fe+2.33+ is bonded to six O2- atoms to form FeO6 octahedra that share edges with two equivalent MnO6 octahedra, edges with four equivalent LiO6 octahedra, and edges with four equivalent FeO6 octahedra. All Fe–O bond lengths are 1.93 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Li1+, one Mn7+, and two Fe+2.33+ atoms. In the second O2- site, O2- is bonded to two equivalent Li1+ and three Fe+2.33+ atoms to form OLi2Fe3 square pyramids that share corners with five equivalent OLi2Fe3 square pyramids and edges with four equivalent OLi2MnFe2 square pyramids. In the third O2- site, O2- is bonded to two equivalent Li1+, one Mn7+, and two equivalent Fe+2.33+ atoms to form OLi2MnFe2 square pyramids that share corners with five equivalent OLi2MnFe2 square pyramids and edges with four equivalent OLi2Fe3 square pyramids.