Materials Data on Li2Cu2F7 by Materials Project

Abstract

Li2Cu2F7 crystallizes in the orthorhombic Pna2_1 space group. The structure is three-dimensional. there are two inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded in a rectangular see-saw-like geometry to four F1- atoms. There are a spread of Li–F bond distances ranging from 1.87–1.97 Å. In the second Li1+ site, Li1+ is bonded to four F1- atoms to form LiF4 tetrahedra that share corners with three equivalent CuF6 octahedra. The corner-sharing octahedra tilt angles range from 49–59°. There are a spread of Li–F bond distances ranging from 1.87–2.00 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 distorted CuF6 octahedra that share corners with three equivalent LiF4 tetrahedra. There are a spread of Cu–F bond distances ranging from 1.83–2.20 Å. In the second Cu+2.50+ site, Cu+2.50+ is bonded in a 6-coordinate geometry to six F1- atoms. There are a spread of Cu–F bond distances ranging from 1.80–2.51 Å. There are seven inequivalent F1- sites. In the first F1- site, F1- is bonded in a distorted trigonal non-coplanar geometry to one Li1+ and two Cu+2.50+ atoms. In the second F1- site, F1- is bonded in a distorted trigonal non-coplanar geometry to one Li1+ and two Cu+2.50+ atoms. In the third F1- site, F1- is bonded in a 4-coordinate geometry to two Li1+ and two Cu+2.50+ atoms. In the fourth F1- site, F1- is bonded in a trigonal planar geometry to one Li1+ and two Cu+2.50+ atoms. In the fifth F1- site, F1- is bonded in a trigonal planar geometry to one Li1+ and two Cu+2.50+ atoms. In the sixth F1- site, F1- is bonded in a bent 120 degrees geometry to one Li1+ and one Cu+2.50+ atom. In the seventh F1- site, F1- is bonded in a bent 120 degrees geometry to one Li1+ and one Cu+2.50+ atom.