Materials Data on Li2CuF4 by Materials Project

Abstract

Li2CuF4 crystallizes in the monoclinic Pc space group. The structure is three-dimensional. there are two inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded to five F1- atoms to form distorted LiF5 trigonal bipyramids that share corners with three equivalent CuF6 octahedra, corners with two equivalent LiF5 trigonal bipyramids, and edges with two equivalent CuF6 octahedra. The corner-sharing octahedra tilt angles range from 44–54°. There are a spread of Li–F bond distances ranging from 1.93–2.10 Å. In the second Li1+ site, Li1+ is bonded in a 4-coordinate geometry to five F1- atoms. There are a spread of Li–F bond distances ranging from 1.94–2.64 Å. Cu2+ is bonded to six F1- atoms to form distorted CuF6 octahedra that share corners with four equivalent CuF6 octahedra, corners with three equivalent LiF5 trigonal bipyramids, and edges with two equivalent LiF5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 42–52°. There are a spread of Cu–F bond distances ranging from 1.92–2.45 Å. There are four inequivalent F1- sites. In the first F1- site, F1- is bonded to three Li1+ and one Cu2+ atom to form distorted corner-sharing FLi3Cu trigonal pyramids. In the second F1- site, F1- is bonded in a 3-coordinate geometry to two Li1+ and two equivalent Cu2+ atoms. In the third F1- site, F1- is bonded to three Li1+ and one Cu2+ atom to form distorted corner-sharing FLi3Cu trigonal pyramids. In the fourth F1- site, F1- is bonded in a 2-coordinate geometry to two Li1+ and two equivalent Cu2+ atoms.