Materials Data on Li3FeF6 by Materials Project

Abstract

Li3FeF6 is Ilmenite-like structured and crystallizes in the trigonal P-31c space group. The structure is three-dimensional. there are two inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded to six equivalent F1- atoms to form distorted LiF6 octahedra that share corners with three equivalent LiF6 octahedra, edges with three equivalent LiF6 octahedra, edges with three equivalent FeF6 octahedra, and a faceface with one LiF6 octahedra. The corner-sharing octahedral tilt angles are 57°. There are three shorter (1.97 Å) and three longer (2.15 Å) Li–F bond lengths. In the second Li1+ site, Li1+ is bonded to six equivalent F1- atoms to form LiF6 octahedra that share corners with six equivalent LiF6 octahedra, corners with six equivalent FeF6 octahedra, and faces with two equivalent LiF6 octahedra. The corner-sharing octahedra tilt angles range from 42–57°. All Li–F bond lengths are 2.11 Å. Fe3+ is bonded to six equivalent F1- atoms to form FeF6 octahedra that share corners with six equivalent LiF6 octahedra and edges with six equivalent LiF6 octahedra. The corner-sharing octahedral tilt angles are 42°. All Fe–F bond lengths are 1.97 Å. F1- is bonded to three Li1+ and one Fe3+ atom to form a mixture of corner and edge-sharing FLi3Fe trigonal pyramids.