DOI: 10.17188/1297929
title: Materials Data on Na3(CoO2)4 by Materials Project

description: Na3(CoO2)4 crystallizes in the orthorhombic Pmn2_1 space group. The structure is three-dimensional. there are three inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are four shorter (2.38 Å) and two longer (2.48 Å) Na–O bond lengths. In the second 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 2.30–2.40 Å. In the third 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 2.32–2.57 Å. There are four inequivalent Co+3.25+ sites. In the first Co+3.25+ site, Co+3.25+ is bonded to six O2- atoms to form edge-sharing CoO6 octahedra. There are a spread of Co–O bond distances ranging from 1.89–1.94 Å. In the second Co+3.25+ site, Co+3.25+ is bonded to six O2- atoms to form edge-sharing CoO6 octahedra. There are a spread of Co–O bond distances ranging from 1.91–1.95 Å. In the third Co+3.25+ site, Co+3.25+ is bonded to six O2- atoms to form edge-sharing CoO6 octahedra. There are a spread of Co–O bond distances ranging from 1.90–1.93 Å. In the fourth Co+3.25+ site, Co+3.25+ is bonded to six O2- atoms to form edge-sharing CoO6 octahedra. There are a spread of Co–O bond distances ranging from 1.92–1.95 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a 5-coordinate geometry to two equivalent Na1+ and three Co+3.25+ atoms. In the second O2- site, O2- is bonded to three Na1+ and three Co+3.25+ atoms to form distorted ONa3Co3 octahedra that share corners with two equivalent ONa3Co3 octahedra, corners with four equivalent ONa2Co3 square pyramids, corners with three equivalent ONa2Co3 trigonal bipyramids, edges with two equivalent ONa3Co3 octahedra, edges with three ONa2Co3 square pyramids, edges with two equivalent ONa2Co3 trigonal bipyramids, and a faceface with one ONa3Co3 octahedra. The corner-sharing octahedral tilt angles are 47°. In the third O2- site, O2- is bonded in a 5-coordinate geometry to two equivalent Na1+ and three Co+3.25+ atoms. In the fourth O2- site, O2- is bonded to two Na1+ and three Co+3.25+ atoms to form distorted ONa2Co3 trigonal bipyramids that share corners with three equivalent ONa3Co3 octahedra, corners with two equivalent ONa2Co3 trigonal bipyramids, edges with two equivalent ONa3Co3 octahedra, and edges with three equivalent ONa2Co3 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 2–39°. In the fifth O2- site, O2- is bonded to three Na1+ and three Co+3.25+ atoms to form distorted ONa3Co3 octahedra that share corners with two equivalent ONa3Co3 octahedra, corners with four equivalent ONa2Co3 square pyramids, corners with three equivalent ONa2Co3 trigonal bipyramids, edges with two equivalent ONa3Co3 octahedra, edges with three ONa2Co3 square pyramids, edges with two equivalent ONa2Co3 trigonal bipyramids, and a faceface with one ONa3Co3 octahedra. The corner-sharing octahedral tilt angles are 47°. In the sixth O2- site, O2- is bonded to two equivalent Na1+ and three Co+3.25+ atoms to form distorted ONa2Co3 square pyramids that share corners with four equivalent ONa3Co3 octahedra, corners with two equivalent ONa2Co3 square pyramids, edges with three ONa3Co3 octahedra, and edges with five ONa2Co3 square pyramids. The corner-sharing octahedra tilt angles range from 1–49°. In the seventh O2- site, O2- is bonded to two Na1+ and three Co+3.25+ atoms to form distorted ONa2Co3 trigonal bipyramids that share corners with three equivalent ONa3Co3 octahedra, corners with two equivalent ONa2Co3 trigonal bipyramids, edges with two equivalent ONa3Co3 octahedra, and edges with three equivalent ONa2Co3 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 2–38°. In the eighth O2- site, O2- is bonded to two equivalent Na1+ and three Co+3.25+ atoms to form ONa2Co3 square pyramids that share corners with four equivalent ONa3Co3 octahedra, corners with two equivalent ONa2Co3 square pyramids, edges with three ONa3Co3 octahedra, and edges with five ONa2Co3 square pyramids. The corner-sharing octahedra tilt angles range from 1–49°.