Materials Data on Li2Cu2F7 by Materials Project

Abstract

Li2Cu2F7 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are two inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded in a 5-coordinate geometry to five F1- atoms. There are a spread of Li–F bond distances ranging from 1.88–2.35 Å. In the second Li1+ site, Li1+ is bonded to six F1- atoms to form distorted LiF6 octahedra that share corners with three CuF6 octahedra, an edgeedge with one LiF6 octahedra, and edges with three CuF6 octahedra. The corner-sharing octahedra tilt angles range from 12–24°. There are a spread of Li–F bond distances ranging from 1.91–2.29 Å. There are two inequivalent Cu+2.50+ sites. In the first Cu+2.50+ site, Cu+2.50+ is bonded to six F1- atoms to form CuF6 octahedra that share a cornercorner with one CuF6 octahedra, corners with two equivalent LiF6 octahedra, an edgeedge with one LiF6 octahedra, and edges with three CuF6 octahedra. The corner-sharing octahedra tilt angles range from 12–21°. There are a spread of Cu–F bond distances ranging from 1.86–2.18 Å. In the second Cu+2.50+ site, Cu+2.50+ is bonded to six F1- atoms to form CuF6 octahedra that share a cornercorner with one LiF6 octahedra, a cornercorner with one CuF6 octahedra, edges with two equivalent LiF6 octahedra, and edges with two equivalent CuF6 octahedra. The corner-sharing octahedra tilt angles range from 21–24°. There are a spread of Cu–F bond distances ranging from 1.91–2.04 Å. There are seven inequivalent F1- sites. In the first F1- site, F1- is bonded in a trigonal non-coplanar geometry to two Li1+ and one Cu+2.50+ atom. In the second F1- site, F1- is bonded in a T-shaped geometry to one Li1+ and two Cu+2.50+ atoms. In the third F1- site, F1- is bonded in a distorted T-shaped geometry to three Cu+2.50+ atoms. In the fourth F1- site, F1- is bonded in a rectangular see-saw-like geometry to two Li1+ and two Cu+2.50+ atoms. In the fifth F1- site, F1- is bonded in a distorted T-shaped geometry to two Li1+ and one Cu+2.50+ atom. In the sixth F1- site, F1- is bonded in a T-shaped geometry to two Li1+ and one Cu+2.50+ atom. In the seventh F1- site, F1- is bonded to two equivalent Li1+ and two Cu+2.50+ atoms to form distorted edge-sharing FLi2Cu2 trigonal pyramids.