Materials Data on Li7VAs4 by Materials Project
Li7VAs4 is Fluorite-derived structured and crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. there are four inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded to four As3- atoms to form LiAs4 tetrahedra that share corners with four equivalent VAs4 tetrahedra, corners with twelve LiAs4 tetrahedra, and edges with six LiAs4 tetrahedra. There are a spread of Li–As bond distances ranging from 2.66–2.74 Å. In the second Li1+ site, Li1+ is bonded to four As3- atoms to form LiAs4 tetrahedra that share corners with sixteen LiAs4 tetrahedra, edges with two equivalent VAs4 tetrahedra, and edges with four LiAs4 tetrahedra. There are two shorter (2.57 Å) and two longer (2.58 Å) Li–As bond lengths. In the third Li1+ site, Li1+ is bonded to four As3- atoms to form LiAs4 tetrahedra that share corners with two equivalent VAs4 tetrahedra, corners with fourteen LiAs4 tetrahedra, an edgeedge with one VAs4 tetrahedra, and edges with five LiAs4 tetrahedra. There are a spread of Li–As bond distances ranging from 2.55–2.71 Å. In the fourth Li1+ site, Li1+ is bonded to four As3- atoms to form LiAs4 tetrahedra that share corners with two equivalent VAs4 tetrahedra, corners with fourteen LiAs4 tetrahedra, an edgeedge with one VAs4 tetrahedra, and edges with five LiAs4 tetrahedra. There are a spread of Li–As bond distances ranging from 2.57–2.69 Å. V5+ is bonded to four As3- atoms to form VAs4 tetrahedra that share corners with sixteen LiAs4 tetrahedra and edges with six LiAs4 tetrahedra. All V–As bond lengths are 2.38 Å. There are two inequivalent As3- sites. In the first As3- site, As3- is bonded in a body-centered cubic geometry to seven Li1+ and one V5+ atom. In the second As3- site, As3- is bonded in a body-centered cubic geometry to seven Li1+ and one V5+ atom.