Materials Data on Nb4Ag2O11 by Materials Project

Abstract

Ag2Nb4O11 crystallizes in the trigonal R-3c space group. The structure is three-dimensional. there are two inequivalent Nb5+ sites. In the first Nb5+ site, Nb5+ is bonded to seven O2- atoms to form distorted NbO7 pentagonal bipyramids that share corners with two equivalent NbO6 octahedra, corners with two equivalent NbO7 pentagonal bipyramids, and edges with four equivalent NbO7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 44°. There are a spread of Nb–O bond distances ranging from 2.00–2.44 Å. In the second Nb5+ site, Nb5+ is bonded to six equivalent O2- atoms to form corner-sharing NbO6 octahedra. All Nb–O bond lengths are 2.02 Å. Ag1+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ag–O bond distances ranging from 2.61–2.93 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to two Nb5+ and two equivalent Ag1+ atoms. In the second O2- site, O2- is bonded in a 2-coordinate geometry to three equivalent Nb5+ atoms. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to three equivalent Nb5+ and one Ag1+ atom.