Materials Data on Li2Fe2P2O8F by Materials Project
Li2Fe2P2O8F crystallizes in the orthorhombic Pbcn space group. The structure is three-dimensional. Li1+ is bonded to four O2- and one F1- atom to form distorted LiO4F trigonal bipyramids that share corners with two equivalent FeO4F square pyramids, corners with four equivalent PO4 tetrahedra, a cornercorner with one LiO4F trigonal bipyramid, an edgeedge with one FeO4F square pyramid, and an edgeedge with one LiO4F trigonal bipyramid. There are a spread of Li–O bond distances ranging from 2.04–2.15 Å. The Li–F bond length is 2.29 Å. Fe+2.50+ is bonded to four O2- and one F1- atom to form distorted FeO4F square pyramids that share corners with four equivalent PO4 tetrahedra, corners with two equivalent LiO4F trigonal bipyramids, an edgeedge with one LiO4F trigonal bipyramid, and a faceface with one FeO4F square pyramid. There are a spread of Fe–O bond distances ranging from 1.96–2.11 Å. The Fe–F bond length is 2.09 Å. P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with four equivalent FeO4F square pyramids and corners with four equivalent LiO4F trigonal bipyramids. There are a spread of P–O bond distances ranging from 1.51–1.60 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Li1+ and one P5+ atom. In the second O2- site, O2- is bonded in a trigonal planar geometry to one Li1+, one Fe+2.50+, and one P5+ atom. In the third O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Fe+2.50+ and one P5+ atom. In the fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Li1+, one Fe+2.50+, and one P5+ atom. F1- is bonded in a distorted rectangular see-saw-like geometry to two equivalent Li1+ and two equivalent Fe+2.50+ atoms.