Materials Data on Na(CoO2)3 by Materials Project

Abstract

Na(CoO2)3 crystallizes in the triclinic P1 space group. The structure is three-dimensional. Na1+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Na–O bond distances ranging from 2.28–2.92 Å. There are three inequivalent Co+3.67+ sites. In the first Co+3.67+ site, Co+3.67+ is bonded to five O2- atoms to form distorted CoO5 trigonal bipyramids that share a cornercorner with one CoO6 octahedra, corners with three equivalent CoO4 tetrahedra, and edges with two equivalent CoO6 octahedra. The corner-sharing octahedral tilt angles are 36°. There are a spread of Co–O bond distances ranging from 1.75–2.21 Å. In the second Co+3.67+ site, Co+3.67+ is bonded to four O2- atoms to form CoO4 tetrahedra that share corners with four equivalent CoO6 octahedra and corners with three equivalent CoO5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 33–71°. There are a spread of Co–O bond distances ranging from 1.79–1.96 Å. In the third Co+3.67+ site, Co+3.67+ is bonded to six O2- atoms to form CoO6 octahedra that share corners with four equivalent CoO4 tetrahedra, a cornercorner with one CoO5 trigonal bipyramid, and edges with two equivalent CoO5 trigonal bipyramids. There are a spread of Co–O bond distances ranging from 1.86–2.02 Å. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Na1+ and three Co+3.67+ atoms. In the second O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+ and two Co+3.67+ atoms. In the third O2- site, O2- is bonded in a 2-coordinate geometry to one Na1+, two Co+3.67+, and one O2- atom. The O–O bond length is 1.47 Å. In the fourth O2- site, O2- is bonded to one Na1+ and three Co+3.67+ atoms to form distorted corner-sharing ONaCo3 tetrahedra. In the fifth O2- site, O2- is bonded to one Na1+ and three Co+3.67+ atoms to form distorted corner-sharing ONaCo3 tetrahedra. In the sixth O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+, two Co+3.67+, and one O2- atom.