Materials Data on Nb2NiO6 by Materials Project

Abstract

NiNb2O6 is zeta iron carbide-derived structured and crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are three inequivalent Nb5+ sites. In the first Nb5+ site, Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with two equivalent NbO6 octahedra, corners with six equivalent NiO6 octahedra, and edges with two equivalent NbO6 octahedra. The corner-sharing octahedra tilt angles range from 47–51°. There are a spread of Nb–O bond distances ranging from 1.95–2.07 Å. In the second Nb5+ site, Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with eight NbO6 octahedra and edges with two equivalent NiO6 octahedra. The corner-sharing octahedra tilt angles range from 45–51°. There are four shorter (2.00 Å) and two longer (2.06 Å) Nb–O bond lengths. In the third Nb5+ site, Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with three equivalent NbO6 octahedra, corners with five equivalent NiO6 octahedra, and edges with two NbO6 octahedra. The corner-sharing octahedra tilt angles range from 43–58°. There are a spread of Nb–O bond distances ranging from 1.91–2.17 Å. Ni2+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with eight NbO6 octahedra, an edgeedge with one NbO6 octahedra, and an edgeedge with one NiO6 octahedra. The corner-sharing octahedra tilt angles range from 43–58°. There are a spread of Ni–O bond distances ranging from 2.04–2.17 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a trigonal planar geometry to two Nb5+ and one Ni2+ atom. In the second O2- site, O2- is bonded in a 3-coordinate geometry to one Nb5+ and two equivalent Ni2+ atoms. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to three Nb5+ atoms. In the fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Nb5+ and one Ni2+ atom. In the fifth O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Nb5+ and one Ni2+ atom.