Materials Data on Li6Cr2O7 by Materials Project

Li6Cr2O7 crystallizes in the monoclinic P2/c space group. The structure is three-dimensional. there are three inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded in a distorted see-saw-like geometry to four O2- atoms. There are a spread of Li–O bond distances ranging from 1.95–2.05 Å. In the second Li1+ site, Li1+ is bonded to five O2- atoms to form distorted LiO5 square pyramids that share corners with three equivalent CrO4 tetrahedra, edges with two equivalent LiO5 square pyramids, and an edgeedge with one CrO4 tetrahedra. There are a spread of Li–O bond distances ranging from 2.05–2.36 Å. In the third Li1+ site, Li1+ is bonded in a rectangular see-saw-like geometry to four O2- atoms. There are a spread of Li–O bond distances ranging from 1.95–2.07 Å. Cr4+ is bonded to four O2- atoms to form CrO4 tetrahedra that share corners with three equivalent LiO5 square pyramids, a cornercorner with one CrO4 tetrahedra, and an edgeedge with one LiO5 square pyramid. There are a spread of Cr–O bond distances ranging from 1.76–1.87 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded to four Li1+ and one Cr4+ atom to form distorted OLi4Cr square pyramids that share a cornercorner with one OLi4Cr square pyramid, corners with two equivalent OLi2Cr2 tetrahedra, and edges with four OLi4Cr square pyramids. In the second O2- site, O2- is bonded to four Li1+ and one Cr4+ atom to form distorted OLi4Cr square pyramids that share a cornercorner with one OLi4Cr square pyramid, a cornercorner with one OLi2Cr2 tetrahedra, and edges with five OLi4Cr square pyramids. In the third O2- site, O2- is bonded in a 5-coordinate geometry to four Li1+ and one Cr4+ atom. In the fourth O2- site, O2- is bonded to two equivalent Li1+ and two equivalent Cr4+ atoms to form distorted corner-sharing OLi2Cr2 tetrahedra.