Materials Data on RbNbO3 by Materials Project

Abstract

RbNbO3 is Pb(Zr_(1-x)Ti_x)O3-like structured and crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are two inequivalent Rb1+ sites. In the first Rb1+ site, Rb1+ is bonded in a 4-coordinate geometry to eight O2- atoms. There are a spread of Rb–O bond distances ranging from 2.70–3.16 Å. In the second Rb1+ site, Rb1+ is bonded in a 4-coordinate geometry to four O2- atoms. There are two shorter (2.82 Å) and two longer (2.91 Å) Rb–O bond lengths. There are two inequivalent Nb5+ sites. In the first Nb5+ site, Nb5+ is bonded to six O2- atoms to form a mixture of distorted corner and edge-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles are 4°. There are a spread of Nb–O bond distances ranging from 1.84–2.37 Å. In the second Nb5+ site, Nb5+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles are 4°. There are a spread of Nb–O bond distances ranging from 1.95–2.10 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded to one Rb1+ and three Nb5+ atoms to form distorted edge-sharing ORbNb3 trigonal pyramids. In the second O2- site, O2- is bonded in a distorted single-bond geometry to three Rb1+ and one Nb5+ atom. In the third O2- site, O2- is bonded in a 2-coordinate geometry to two Rb1+ and two Nb5+ atoms. In the fourth O2- site, O2- is bonded in a linear geometry to two equivalent Rb1+ and two Nb5+ atoms.