DOI: 10.17188/1296199
title: Materials Data on Li2Co4OF8 by Materials Project

description: Li2Co4OF8 is Ilmenite-derived structured and crystallizes in the monoclinic Cc space group. The structure is three-dimensional. there are two inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded to six F1- atoms to form LiF6 octahedra that share corners with nine CoOF5 octahedra, edges with three equivalent CoF6 octahedra, and a faceface with one LiOF5 octahedra. The corner-sharing octahedra tilt angles range from 44–64°. There are a spread of Li–F bond distances ranging from 2.02–2.14 Å. In the second Li1+ site, Li1+ is bonded to one O2- and five F1- atoms to form distorted LiOF5 octahedra that share corners with nine CoOF5 octahedra, edges with three equivalent CoOF5 octahedra, and a faceface with one LiF6 octahedra. The corner-sharing octahedra tilt angles range from 46–63°. The Li–O bond length is 1.98 Å. There are a spread of Li–F bond distances ranging from 1.98–2.29 Å. There are four inequivalent Co2+ sites. In the first Co2+ site, Co2+ is bonded to one O2- and five F1- atoms to form CoOF5 octahedra that share corners with three equivalent LiF6 octahedra, corners with six CoF6 octahedra, edges with three equivalent LiOF5 octahedra, and a faceface with one CoOF5 octahedra. The corner-sharing octahedra tilt angles range from 44–62°. The Co–O bond length is 1.98 Å. There are a spread of Co–F bond distances ranging from 2.05–2.26 Å. In the second Co2+ site, Co2+ is bonded to one O2- and five F1- atoms to form CoOF5 octahedra that share corners with three equivalent CoF6 octahedra, corners with six LiF6 octahedra, edges with three equivalent CoOF5 octahedra, and a faceface with one CoOF5 octahedra. The corner-sharing octahedra tilt angles range from 44–64°. The Co–O bond length is 1.97 Å. There are a spread of Co–F bond distances ranging from 2.07–2.27 Å. In the third Co2+ site, Co2+ is bonded to six F1- atoms to form CoF6 octahedra that share corners with three equivalent LiOF5 octahedra, corners with six CoOF5 octahedra, edges with three equivalent LiF6 octahedra, and a faceface with one CoOF5 octahedra. The corner-sharing octahedra tilt angles range from 44–62°. There are a spread of Co–F bond distances ranging from 2.00–2.16 Å. In the fourth Co2+ site, Co2+ is bonded to one O2- and five F1- atoms to form distorted CoOF5 octahedra that share corners with three equivalent CoOF5 octahedra, corners with six LiOF5 octahedra, edges with three equivalent CoOF5 octahedra, and a faceface with one CoF6 octahedra. The corner-sharing octahedra tilt angles range from 44–63°. The Co–O bond length is 1.92 Å. There are a spread of Co–F bond distances ranging from 2.03–2.27 Å. O2- is bonded to one Li1+ and three Co2+ atoms to form distorted OLiCo3 trigonal pyramids that share corners with six FLi2Co2 trigonal pyramids and edges with two FLi2Co2 trigonal pyramids. There are eight inequivalent F1- sites. In the first F1- site, F1- is bonded to two Li1+ and two Co2+ atoms to form distorted FLi2Co2 trigonal pyramids that share corners with two equivalent OLiCo3 trigonal pyramids, corners with six FLi2Co2 trigonal pyramids, and edges with three FLiCo3 trigonal pyramids. In the second F1- site, F1- is bonded to one Li1+ and three Co2+ atoms to form distorted FLiCo3 trigonal pyramids that share corners with two equivalent OLiCo3 trigonal pyramids, corners with six FLi2Co2 trigonal pyramids, and edges with two FLi2Co2 trigonal pyramids. In the third F1- site, F1- is bonded in a 4-coordinate geometry to one Li1+ and three Co2+ atoms. In the fourth F1- site, F1- is bonded to two Li1+ and two Co2+ atoms to form distorted FLi2Co2 trigonal pyramids that share corners with two equivalent OLiCo3 trigonal pyramids, corners with eight FLi2Co2 trigonal pyramids, and edges with two FLi2Co2 trigonal pyramids. In the fifth F1- site, F1- is bonded to one Li1+ and three Co2+ atoms to form distorted FLiCo3 trigonal pyramids that share corners with six FLi2Co2 trigonal pyramids, an edgeedge with one OLiCo3 trigonal pyramid, and edges with two FLiCo3 trigonal pyramids. In the sixth F1- site, F1- is bonded in a distorted see-saw-like geometry to one Li1+ and three Co2+ atoms. In the seventh F1- site, F1- is bonded to two Li1+ and two Co2+ atoms to form distorted FLi2Co2 trigonal pyramids that share corners with six FLi2Co2 trigonal pyramids, an edgeedge with one OLiCo3 trigonal pyramid, and edges with three FLi2Co2 trigonal pyramids. In the eighth F1- site, F1- is bonded in a 4-coordinate geometry to one Li1+ and three Co2+ atoms.