Materials Data on Na3VP2O9 by Materials Project
Na3VP2O9 crystallizes in the monoclinic P2_1/m 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 2.28–2.86 Å. In the second Na1+ site, Na1+ is bonded in a 3-coordinate geometry to six O2- atoms. There are a spread of Na–O bond distances ranging from 2.23–2.98 Å. V5+ is bonded to six O2- atoms to form VO6 octahedra that share corners with five PO4 tetrahedra. There are a spread of V–O bond distances ranging from 1.66–2.02 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 four equivalent VO6 octahedra. The corner-sharing octahedra tilt angles range from 34–53°. All P–O bond lengths are 1.55 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one VO6 octahedra. The corner-sharing octahedral tilt angles are 51°. There are a spread of P–O bond distances ranging from 1.54–1.63 Å. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Na1+, one V5+, and one P5+ atom. In the second O2- site, O2- is bonded in a 2-coordinate geometry to two Na1+, one V5+, and one P5+ atom. In the third O2- site, O2- is bonded in a single-bond geometry to three Na1+ and one V5+ atom. In the fourth O2- site, O2- is bonded in a bent 150 degrees geometry to one V5+ and one P5+ atom. In the fifth O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Na1+, one V5+, and one P5+ atom. In the sixth O2- site, O2- is bonded in a distorted trigonal pyramidal geometry to three Na1+ and one P5+ atom. In the seventh O2- site, O2- is bonded in a 3-coordinate geometry to three Na1+ and one P5+ atom.