Materials Data on Nb4Pb3O13 by Materials Project

Abstract

Pb3Nb4O13 crystallizes in the trigonal R3m space group. The structure is three-dimensional. there are two inequivalent Nb5+ sites. In the first Nb5+ site, Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with six equivalent NbO6 octahedra and edges with six equivalent PbO7 hexagonal pyramids. The corner-sharing octahedra tilt angles range from 40–42°. All Nb–O bond lengths are 2.01 Å. In the second Nb5+ site, Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with six NbO6 octahedra and edges with four equivalent PbO7 hexagonal pyramids. The corner-sharing octahedra tilt angles range from 38–42°. There are a spread of Nb–O bond distances ranging from 2.01–2.04 Å. Pb2+ is bonded to seven O2- atoms to form distorted PbO7 hexagonal pyramids that share corners with two equivalent PbO7 hexagonal pyramids, edges with two equivalent PbO7 hexagonal pyramids, and edges with six NbO6 octahedra. There are a spread of Pb–O bond distances ranging from 2.22–2.76 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a trigonal non-coplanar geometry to three equivalent Pb2+ atoms. In the second O2- site, O2- is bonded in a 2-coordinate geometry to two Nb5+ and two equivalent Pb2+ atoms. In the third O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two equivalent Nb5+ and one Pb2+ atom. In the fourth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two Nb5+ and two equivalent Pb2+ atoms. In the fifth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two equivalent Nb5+ and one Pb2+ atom.