Materials Data on LiFeF3 by Materials Project

Abstract

LiFeF3 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are three inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded to four F1- atoms to form LiF4 trigonal pyramids that share corners with four FeF6 octahedra and corners with two LiF4 tetrahedra. The corner-sharing octahedra tilt angles range from 49–70°. There are a spread of Li–F bond distances ranging from 1.78–1.98 Å. In the second Li1+ site, Li1+ is bonded to four F1- atoms to form LiF4 tetrahedra that share corners with five FeF6 octahedra, a cornercorner with one LiF4 tetrahedra, and a cornercorner with one LiF4 trigonal pyramid. The corner-sharing octahedra tilt angles range from 55–70°. There are a spread of Li–F bond distances ranging from 1.81–1.95 Å. In the third Li1+ site, Li1+ is bonded to four F1- atoms to form LiF4 tetrahedra that share corners with five FeF6 octahedra, a cornercorner with one LiF4 tetrahedra, and a cornercorner with one LiF4 trigonal pyramid. The corner-sharing octahedra tilt angles range from 44–65°. There are a spread of Li–F bond distances ranging from 1.87–1.97 Å. There are three inequivalent Fe2+ sites. In the first Fe2+ site, Fe2+ is bonded in a 5-coordinate geometry to five F1- atoms. There are a spread of Fe–F bond distances ranging from 1.87–2.32 Å. In the second Fe2+ site, Fe2+ is bonded to six F1- atoms to form FeF6 octahedra that share corners with four LiF4 tetrahedra, corners with two equivalent LiF4 trigonal pyramids, and edges with three FeF6 octahedra. There are a spread of Fe–F bond distances ranging from 2.02–2.22 Å. In the third Fe2+ site, Fe2+ is bonded to six F1- atoms to form distorted FeF6 octahedra that share corners with six LiF4 tetrahedra, corners with two equivalent LiF4 trigonal pyramids, and edges with three FeF6 octahedra. There are a spread of Fe–F bond distances ranging from 1.98–2.24 Å. There are nine inequivalent F1- sites. In the first F1- site, F1- is bonded in a bent 150 degrees geometry to one Li1+ and one Fe2+ atom. In the second F1- site, F1- is bonded in a distorted trigonal non-coplanar geometry to one Li1+ and two Fe2+ atoms. In the third F1- site, F1- is bonded to one Li1+ and three Fe2+ atoms to form a mixture of distorted edge and corner-sharing FLiFe3 tetrahedra. In the fourth F1- site, F1- is bonded in a 4-coordinate geometry to one Li1+ and three Fe2+ atoms. In the fifth F1- site, F1- is bonded to one Li1+ and three Fe2+ atoms to form a mixture of distorted edge and corner-sharing FLiFe3 tetrahedra. In the sixth F1- site, F1- is bonded in a distorted trigonal planar geometry to two Li1+ and one Fe2+ atom. In the seventh F1- site, F1- is bonded in a distorted trigonal planar geometry to two Li1+ and one Fe2+ atom. In the eighth F1- site, F1- is bonded in a distorted trigonal non-coplanar geometry to one Li1+ and two Fe2+ atoms. In the ninth F1- site, F1- is bonded in a distorted T-shaped geometry to two Li1+ and one Fe2+ atom.