DOI: 10.17188/1304365
title: Materials Data on Na7Co3O8 by Materials Project

description: Na7Co3O8 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are seven inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to six O2- atoms to form distorted NaO6 octahedra that share corners with seven NaO6 octahedra, a cornercorner with one NaO4 tetrahedra, corners with five CoO4 tetrahedra, edges with two equivalent NaO6 octahedra, an edgeedge with one CoO4 tetrahedra, edges with two equivalent NaO4 tetrahedra, and a faceface with one NaO6 octahedra. The corner-sharing octahedra tilt angles range from 14–63°. There are a spread of Na–O bond distances ranging from 2.36–2.88 Å. In the second Na1+ site, Na1+ is bonded to six O2- atoms to form distorted NaO6 octahedra that share corners with three equivalent NaO6 octahedra, a cornercorner with one NaO4 tetrahedra, corners with three CoO4 tetrahedra, edges with two NaO6 octahedra, an edgeedge with one NaO4 tetrahedra, edges with three CoO4 tetrahedra, and a faceface with one NaO6 octahedra. The corner-sharing octahedra tilt angles range from 55–63°. There are a spread of Na–O bond distances ranging from 2.30–2.60 Å. In the third Na1+ site, Na1+ is bonded to four O2- atoms to form distorted NaO4 tetrahedra that share corners with three NaO6 octahedra, corners with two CoO4 tetrahedra, edges with four NaO6 octahedra, and an edgeedge with one CoO4 tetrahedra. The corner-sharing octahedra tilt angles range from 46–79°. There are a spread of Na–O bond distances ranging from 2.23–2.35 Å. In the fourth Na1+ site, Na1+ is bonded in a 5-coordinate geometry to six O2- atoms. There are a spread of Na–O bond distances ranging from 2.35–3.05 Å. In the fifth Na1+ site, Na1+ is bonded in a 5-coordinate geometry to six O2- atoms. There are a spread of Na–O bond distances ranging from 2.29–2.97 Å. In the sixth Na1+ site, Na1+ is bonded to six O2- atoms to form distorted NaO6 octahedra that share corners with two equivalent NaO6 octahedra, a cornercorner with one NaO4 tetrahedra, corners with three CoO4 tetrahedra, edges with two NaO6 octahedra, an edgeedge with one NaO4 tetrahedra, and edges with three CoO4 tetrahedra. The corner-sharing octahedra tilt angles range from 45–59°. There are a spread of Na–O bond distances ranging from 2.31–2.56 Å. In the seventh Na1+ site, Na1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Na–O bond distances ranging from 2.34–2.88 Å. There are three inequivalent Co3+ sites. In the first Co3+ site, Co3+ is bonded to four O2- atoms to form CoO4 tetrahedra that share corners with five NaO6 octahedra, a cornercorner with one NaO4 tetrahedra, a cornercorner with one CoO4 tetrahedra, edges with three NaO6 octahedra, and an edgeedge with one CoO4 tetrahedra. The corner-sharing octahedra tilt angles range from 17–65°. There are a spread of Co–O bond distances ranging from 1.82–1.97 Å. In the second Co3+ site, Co3+ is bonded to four O2- atoms to form CoO4 tetrahedra that share corners with three NaO6 octahedra, corners with two CoO4 tetrahedra, edges with two NaO6 octahedra, and an edgeedge with one NaO4 tetrahedra. The corner-sharing octahedra tilt angles range from 50–54°. There are a spread of Co–O bond distances ranging from 1.79–2.02 Å. In the third Co3+ site, Co3+ is bonded to four O2- atoms to form CoO4 tetrahedra that share corners with three NaO6 octahedra, a cornercorner with one NaO4 tetrahedra, a cornercorner with one CoO4 tetrahedra, edges with two equivalent NaO6 octahedra, and an edgeedge with one CoO4 tetrahedra. The corner-sharing octahedra tilt angles range from 24–47°. There are a spread of Co–O bond distances ranging from 1.81–1.97 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a 7-coordinate geometry to six Na1+ and one Co3+ atom. In the second O2- site, O2- is bonded in a 6-coordinate geometry to four Na1+ and two equivalent Co3+ atoms. In the third O2- site, O2- is bonded in a 6-coordinate geometry to five Na1+ and one Co3+ atom. In the fourth O2- site, O2- is bonded in a 7-coordinate geometry to six Na1+ and one Co3+ atom. In the fifth O2- site, O2- is bonded in a 7-coordinate geometry to five Na1+ and two Co3+ atoms. In the sixth O2- site, O2- is bonded in a 6-coordinate geometry to five Na1+ and one Co3+ atom. In the seventh O2- site, O2- is bonded in a 6-coordinate geometry to four Na1+ and two equivalent Co3+ atoms. In the eighth O2- site, O2- is bonded in a 7-coordinate geometry to five Na1+ and two Co3+ atoms.