Materials Data on Li2V2O5F2 by Materials Project
Li2V2O5F2 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are two inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded to two O2- and two F1- atoms to form distorted LiO2F2 tetrahedra that share corners with five VO4F trigonal bipyramids. There are one shorter (2.02 Å) and one longer (2.08 Å) Li–O bond lengths. There is one shorter (1.89 Å) and one longer (2.03 Å) Li–F bond length. In the second Li1+ site, Li1+ is bonded in a 5-coordinate geometry to four O2- and one F1- atom. There are a spread of Li–O bond distances ranging from 2.03–2.35 Å. The Li–F bond length is 1.99 Å. There are two inequivalent V5+ sites. In the first V5+ site, V5+ is bonded to four O2- and one F1- atom to form distorted VO4F trigonal bipyramids that share a cornercorner with one LiO2F2 tetrahedra, a cornercorner with one VO4F trigonal bipyramid, and an edgeedge with one VO4F trigonal bipyramid. There are a spread of V–O bond distances ranging from 1.64–1.94 Å. The V–F bond length is 1.94 Å. In the second V5+ site, V5+ is bonded to four O2- and one F1- atom to form VO4F trigonal bipyramids that share corners with four equivalent LiO2F2 tetrahedra, a cornercorner with one VO4F trigonal bipyramid, and an edgeedge with one VO4F trigonal bipyramid. There are a spread of V–O bond distances ranging from 1.65–1.98 Å. The V–F bond length is 1.87 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two equivalent Li1+ and two equivalent V5+ atoms. In the second O2- site, O2- is bonded in a 2-coordinate geometry to one Li1+ and one V5+ atom. In the third O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+ and two V5+ atoms. In the fourth O2- site, O2- is bonded in a distorted T-shaped geometry to one Li1+ and two equivalent V5+ atoms. In the fifth O2- site, O2- is bonded in a linear geometry to one Li1+ and one V5+ atom. There are two inequivalent F1- sites. In the first F1- site, F1- is bonded in a 3-coordinate geometry to two Li1+ and one V5+ atom. In the second F1- site, F1- is bonded in a distorted bent 150 degrees geometry to one Li1+ and one V5+ atom.