Materials Data on Na7V2O6 by Materials Project

Abstract

Na7V2O6 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. there are four inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to four O2- atoms to form a mixture of edge and corner-sharing NaO4 trigonal pyramids. There are a spread of Na–O bond distances ranging from 2.33–2.45 Å. In the second Na1+ site, Na1+ is bonded to four O2- atoms to form a mixture of edge and corner-sharing NaO4 trigonal pyramids. There are a spread of Na–O bond distances ranging from 2.34–2.39 Å. In the third Na1+ site, Na1+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Na–O bond distances ranging from 2.44–2.71 Å. In the fourth Na1+ site, Na1+ is bonded to four O2- atoms to form a mixture of distorted edge and corner-sharing NaO4 trigonal pyramids. There are two shorter (2.42 Å) and two longer (2.48 Å) Na–O bond lengths. V+2.50+ is bonded in a trigonal planar geometry to three O2- atoms. There are a spread of V–O bond distances ranging from 1.82–1.87 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded to five Na1+ and one V+2.50+ atom to form a mixture of distorted face, edge, and corner-sharing ONa5V octahedra. The corner-sharing octahedra tilt angles range from 50–55°. In the second O2- site, O2- is bonded to five Na1+ and one V+2.50+ atom to form a mixture of distorted edge and corner-sharing ONa5V octahedra. The corner-sharing octahedra tilt angles range from 40–55°. In the third O2- site, O2- is bonded in a 6-coordinate geometry to five Na1+ and one V+2.50+ atom.