DOI: 10.17188/1296231
title: Materials Data on Na4V3O8 by Materials Project

description: Na4V3O8 is Krennerite-derived structured and crystallizes in the monoclinic P2_1/m space group. The structure is three-dimensional. there are four inequivalent Na1+ sites. In the first 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 2.25–2.69 Å. In the second Na1+ site, Na1+ is bonded to six O2- atoms to form distorted NaO6 octahedra that share corners with two equivalent NaO6 octahedra, corners with two equivalent VO6 octahedra, and edges with five VO6 octahedra. The corner-sharing octahedra tilt angles range from 1–29°. There are a spread of Na–O bond distances ranging from 2.20–2.54 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 2.23–2.57 Å. In the fourth 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 2.23–2.58 Å. There are three inequivalent V4+ sites. In the first V4+ site, V4+ is bonded to six O2- atoms to form distorted VO6 octahedra that share corners with two equivalent VO6 octahedra, an edgeedge with one NaO6 octahedra, and edges with five VO6 octahedra. The corner-sharing octahedral tilt angles are 19°. There are a spread of V–O bond distances ranging from 1.71–2.17 Å. In the second V4+ site, V4+ is bonded to six O2- atoms to form VO6 octahedra that share corners with two equivalent NaO6 octahedra, corners with two equivalent VO6 octahedra, edges with two equivalent NaO6 octahedra, and edges with three VO6 octahedra. The corner-sharing octahedra tilt angles range from 1–14°. There are a spread of V–O bond distances ranging from 1.79–2.15 Å. In the third V4+ site, V4+ is bonded to six O2- atoms to form VO6 octahedra that share corners with two equivalent VO6 octahedra, edges with two equivalent NaO6 octahedra, and edges with four VO6 octahedra. The corner-sharing octahedral tilt angles are 14°. There are a spread of V–O bond distances ranging from 1.84–2.15 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded to one Na1+ and four V4+ atoms to form distorted ONaV4 square pyramids that share corners with three ONaV4 square pyramids, edges with three equivalent ONa3V3 octahedra, and edges with two equivalent ONaV4 square pyramids. In the second O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to three Na1+ and one V4+ atom. In the third O2- site, O2- is bonded in a 6-coordinate geometry to five Na1+ and one V4+ atom. In the fourth O2- site, O2- is bonded to three Na1+ and two V4+ atoms to form distorted ONa3V2 square pyramids that share corners with two equivalent ONa3V3 octahedra, corners with three ONaV4 square pyramids, and edges with four ONa3V3 octahedra. The corner-sharing octahedra tilt angles range from 10–15°. In the fifth O2- site, O2- is bonded to three Na1+ and three V4+ atoms to form distorted ONa3V3 octahedra that share corners with two equivalent ONa3V3 octahedra, an edgeedge with one ONa3V3 octahedra, and edges with five ONaV4 square pyramids. The corner-sharing octahedral tilt angles are 14°. In the sixth O2- site, O2- is bonded in a 5-coordinate geometry to three Na1+ and two V4+ atoms. In the seventh O2- site, O2- is bonded to three Na1+ and three equivalent V4+ atoms to form distorted ONa3V3 octahedra that share corners with two equivalent ONa3V3 octahedra, corners with two equivalent ONa3V2 square pyramids, edges with three ONa3V3 octahedra, and edges with two equivalent ONa3V2 square pyramids. The corner-sharing octahedral tilt angles are 14°. In the eighth O2- site, O2- is bonded in a 5-coordinate geometry to three equivalent Na1+ and two V4+ atoms.