Materials Data on Li3CuF6 by Materials Project

Abstract

Li3CuF6 is Ilmenite-like structured and crystallizes in the trigonal R-3 space group. The structure is three-dimensional. Li1+ is bonded to six F1- atoms to form distorted LiF6 pentagonal pyramids that share corners with two CuF6 octahedra, corners with four equivalent LiF6 pentagonal pyramids, edges with two CuF6 octahedra, and edges with four equivalent LiF6 pentagonal pyramids. The corner-sharing octahedra tilt angles range from 36–43°. There are a spread of Li–F bond distances ranging from 1.97–2.21 Å. There are two inequivalent Cu3+ sites. In the first Cu3+ site, Cu3+ is bonded to six equivalent F1- atoms to form CuF6 octahedra that share corners with six equivalent LiF6 pentagonal pyramids and edges with six equivalent LiF6 pentagonal pyramids. All Cu–F bond lengths are 1.92 Å. In the second Cu3+ site, Cu3+ is bonded to six equivalent F1- atoms to form CuF6 octahedra that share corners with six equivalent LiF6 pentagonal pyramids and edges with six equivalent LiF6 pentagonal pyramids. All Cu–F bond lengths are 1.92 Å. There are two inequivalent F1- sites. In the first F1- site, F1- is bonded to three equivalent Li1+ and one Cu3+ atom to form a mixture of distorted edge and corner-sharing FLi3Cu trigonal pyramids. In the second F1- site, F1- is bonded in a distorted see-saw-like geometry to three equivalent Li1+ and one Cu3+ atom.