Materials Data on Li3Fe2F9 by Materials Project
Li3Fe2F9 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are three inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded in a trigonal non-coplanar geometry to three F1- atoms. There is two shorter (1.87 Å) and one longer (2.04 Å) Li–F bond length. In the second Li1+ site, Li1+ is bonded in a trigonal non-coplanar geometry to three F1- atoms. There is two shorter (1.84 Å) and one longer (1.86 Å) Li–F bond length. In the third Li1+ site, Li1+ is bonded in a distorted see-saw-like geometry to four F1- atoms. There are a spread of Li–F bond distances ranging from 1.87–2.26 Å. Fe3+ is bonded to six F1- atoms to form distorted face-sharing FeF6 octahedra. There are a spread of Fe–F bond distances ranging from 1.87–2.11 Å. There are six inequivalent F1- sites. In the first F1- site, F1- is bonded in a tetrahedral geometry to two Li1+ and two equivalent Fe3+ atoms. In the second F1- site, F1- is bonded in a bent 150 degrees geometry to one Li1+ and one Fe3+ atom. In the third F1- site, F1- is bonded in a bent 120 degrees geometry to one Li1+ and one Fe3+ atom. In the fourth F1- site, F1- is bonded in a 3-coordinate geometry to one Li1+ and two equivalent Fe3+ atoms. In the fifth F1- site, F1- is bonded in a bent 150 degrees geometry to one Li1+ and one Fe3+ atom. In the sixth F1- site, F1- is bonded in a 3-coordinate geometry to one Li1+ and two equivalent Fe3+ atoms.