Materials Data on Li2W(OF2)2 by Materials Project

Abstract

Li2W(OF2)2 is zeta iron carbide-derived structured and crystallizes in the orthorhombic Pbcn space group. The structure is three-dimensional. there are two inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded in a 6-coordinate geometry to six F1- atoms. There are a spread of Li–F bond distances ranging from 1.96–2.33 Å. In the second Li1+ site, Li1+ is bonded to four equivalent O2- and two equivalent F1- atoms to form LiO4F2 octahedra that share corners with six equivalent WO2F4 octahedra and edges with two equivalent LiO4F2 octahedra. The corner-sharing octahedra tilt angles range from 46–53°. All Li–O bond lengths are 2.17 Å. Both Li–F bond lengths are 2.09 Å. W6+ is bonded to two equivalent O2- and four F1- atoms to form distorted WO2F4 octahedra that share corners with six equivalent LiO4F2 octahedra. The corner-sharing octahedra tilt angles range from 46–53°. Both W–O bond lengths are 1.78 Å. There are two shorter (1.96 Å) and two longer (2.08 Å) W–F bond lengths. O2- is bonded in a 3-coordinate geometry to two equivalent Li1+ and one W6+ atom. There are two inequivalent F1- sites. In the first F1- site, F1- is bonded in a distorted trigonal planar geometry to two equivalent Li1+ and one W6+ atom. In the second F1- site, F1- is bonded in a distorted trigonal planar geometry to two Li1+ and one W6+ atom.