Materials Data on Nb2P2O9 by Materials Project
Nb2P2O9 crystallizes in the orthorhombic Cmce space group. The structure is three-dimensional. Nb4+ is bonded to seven O2- atoms to form NbO7 pentagonal bipyramids that share a cornercorner with one NbO7 pentagonal bipyramid, corners with four equivalent PO4 tetrahedra, edges with two equivalent NbO7 pentagonal bipyramids, and an edgeedge with one PO4 tetrahedra. There are a spread of Nb–O bond distances ranging from 1.91–2.25 Å. P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with four equivalent NbO7 pentagonal bipyramids and an edgeedge with one NbO7 pentagonal bipyramid. There are a spread of P–O bond distances ranging from 1.50–1.58 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to two equivalent Nb4+ and one P5+ atom. In the second O2- site, O2- is bonded in a linear geometry to two equivalent Nb4+ atoms. In the third O2- site, O2- is bonded in a linear geometry to one Nb4+ and one P5+ atom. In the fourth O2- site, O2- is bonded in a distorted linear geometry to one Nb4+ and one P5+ atom.