Materials Data on Na2V(PO4)2 by Materials Project

Abstract

Na2VP2O8 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Na–O bond distances ranging from 2.33–3.00 Å. In the second Na1+ site, Na1+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Na–O bond distances ranging from 2.38–2.66 Å. V4+ is bonded to six O2- atoms to form distorted VO6 octahedra that share corners with five PO4 tetrahedra. There are a spread of V–O bond distances ranging from 1.66–2.16 Å. There are two inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with three equivalent VO6 octahedra and a cornercorner with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 43–50°. There are a spread of P–O bond distances ranging from 1.53–1.61 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent VO6 octahedra and a cornercorner with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 41–48°. There are a spread of P–O bond distances ranging from 1.52–1.65 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one V4+, and one P5+ atom. In the second O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Na1+, one V4+, and one P5+ atom. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to one Na1+, one V4+, and one P5+ atom. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one V4+, and one P5+ atom. In the fifth O2- site, O2- is bonded in a 1-coordinate geometry to two equivalent Na1+ and one V4+ atom. In the sixth O2- site, O2- is bonded to three Na1+ and one P5+ atom to form distorted corner-sharing ONa3P tetrahedra. In the seventh O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Na1+ and two P5+ atoms. In the eighth O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Na1+, one V4+, and one P5+ atom.