Materials Data on Na4CoO3 by Materials Project

Abstract

Na4CoO3 crystallizes in the monoclinic Cc 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 distorted edge and corner-sharing NaO4 trigonal pyramids. There are a spread of Na–O bond distances ranging from 2.29–2.83 Å. In the second Na1+ site, Na1+ is bonded in a distorted see-saw-like geometry to four O2- atoms. There are a spread of Na–O bond distances ranging from 2.36–2.55 Å. In the third Na1+ site, Na1+ is bonded to four O2- atoms to form a mixture of distorted edge and corner-sharing NaO4 trigonal pyramids. There are a spread of Na–O bond distances ranging from 2.31–2.39 Å. In the fourth Na1+ site, Na1+ is bonded in a trigonal planar geometry to three O2- atoms. There are a spread of Na–O bond distances ranging from 2.24–2.31 Å. Co2+ is bonded in a trigonal planar geometry to three O2- atoms. There are a spread of Co–O bond distances ranging from 1.83–1.93 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded to five Na1+ and one Co2+ atom to form a mixture of distorted edge and corner-sharing ONa5Co octahedra. The corner-sharing octahedra tilt angles range from 44–57°. In the second O2- site, O2- is bonded to five Na1+ and one Co2+ atom to form a mixture of edge and corner-sharing ONa5Co octahedra. The corner-sharing octahedra tilt angles range from 44–61°. In the third O2- site, O2- is bonded in a 6-coordinate geometry to five Na1+ and one Co2+ atom.