DOI: 10.17188/1695383
title: Materials Data on Li4V9O18 by Materials Project

description: Li4V9O18 crystallizes in the orthorhombic Pbam space group. The structure is three-dimensional. there are two inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded to five O2- atoms to form distorted LiO5 trigonal bipyramids that share corners with five VO6 octahedra, edges with four VO6 octahedra, and edges with two equivalent LiO5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 13–78°. There are a spread of Li–O bond distances ranging from 2.14–2.41 Å. In the second Li1+ site, Li1+ is bonded in a 2-coordinate geometry to eight O2- atoms. There are a spread of Li–O bond distances ranging from 2.19–2.61 Å. There are five inequivalent V+3.56+ sites. In the first V+3.56+ site, V+3.56+ is bonded to six O2- atoms to form VO6 octahedra that share corners with four equivalent LiO5 trigonal bipyramids, edges with six VO6 octahedra, and edges with two equivalent LiO5 trigonal bipyramids. There is two shorter (1.89 Å) and four longer (2.02 Å) V–O bond length. In the second V+3.56+ site, V+3.56+ is bonded to six O2- atoms to form VO6 octahedra that share corners with two equivalent VO6 octahedra, corners with three equivalent LiO5 trigonal bipyramids, edges with four VO6 octahedra, and an edgeedge with one LiO5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 49°. There are a spread of V–O bond distances ranging from 1.87–2.14 Å. In the third V+3.56+ site, V+3.56+ is bonded to five O2- atoms to form VO5 square pyramids that share corners with six VO6 octahedra and edges with two equivalent VO5 square pyramids. The corner-sharing octahedra tilt angles range from 51–64°. There are a spread of V–O bond distances ranging from 1.98–2.06 Å. In the fourth V+3.56+ site, V+3.56+ is bonded to six O2- atoms to form VO6 octahedra that share corners with two equivalent VO6 octahedra, corners with two equivalent VO5 square pyramids, edges with four VO6 octahedra, and edges with two equivalent LiO5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 49°. There are a spread of V–O bond distances ranging from 2.00–2.05 Å. In the fifth V+3.56+ site, V+3.56+ is bonded to six O2- atoms to form VO6 octahedra that share corners with four equivalent VO5 square pyramids and edges with four VO6 octahedra. There are a spread of V–O bond distances ranging from 1.89–2.03 Å. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded to two equivalent Li1+ and three V+3.56+ atoms to form a mixture of edge and corner-sharing OLi2V3 square pyramids. In the second O2- site, O2- is bonded in a 5-coordinate geometry to two equivalent Li1+ and three V+3.56+ atoms. In the third O2- site, O2- is bonded in a 3-coordinate geometry to three V+3.56+ atoms. In the fourth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+ and three V+3.56+ atoms. In the fifth O2- site, O2- is bonded in a distorted T-shaped geometry to three V+3.56+ atoms. In the sixth O2- site, O2- is bonded in a square co-planar geometry to two equivalent Li1+ and two equivalent V+3.56+ atoms. In the seventh O2- site, O2- is bonded to two equivalent Li1+ and three V+3.56+ atoms to form a mixture of distorted edge and corner-sharing OLi2V3 square pyramids. In the eighth O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Li1+ and three V+3.56+ atoms. In the ninth O2- site, O2- is bonded to two equivalent Li1+ and three V+3.56+ atoms to form a mixture of distorted edge and corner-sharing OLi2V3 trigonal bipyramids.