Materials Data on LiFe2F7 by Materials Project
LiFe2F7 crystallizes in the monoclinic P2/c space group. The structure is three-dimensional. Li1+ is bonded in a see-saw-like geometry to four F1- atoms. There are two shorter (1.83 Å) and two longer (2.28 Å) Li–F bond lengths. Fe3+ is bonded to six F1- atoms to form a mixture of edge and corner-sharing FeF6 octahedra. The corner-sharing octahedral tilt angles are 47°. There are a spread of Fe–F bond distances ranging from 1.86–2.04 Å. There are four inequivalent F1- sites. In the first F1- site, F1- is bonded in a distorted bent 120 degrees geometry to two equivalent Fe3+ atoms. In the second F1- site, F1- is bonded in a trigonal planar geometry to one Li1+ and two equivalent Fe3+ atoms. In the third F1- site, F1- is bonded in a water-like geometry to two equivalent Fe3+ atoms. In the fourth F1- site, F1- is bonded in a bent 150 degrees geometry to one Li1+ and one Fe3+ atom.