Materials Data on Nb2NiO6 by Materials Project
NiNb2O6 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 in a square co-planar geometry to four O2- atoms. There are two shorter (2.07 Å) and two longer (2.12 Å) Nb–O bond lengths. In the second Nb5+ site, Nb5+ is bonded in a 6-coordinate geometry to six O2- atoms. There are four shorter (1.99 Å) and two longer (2.38 Å) Nb–O bond lengths. In the third Nb5+ site, Nb5+ is bonded to seven O2- atoms to form distorted edge-sharing NbO7 pentagonal bipyramids. There are a spread of Nb–O bond distances ranging from 1.99–2.20 Å. Ni2+ is bonded in a 3-coordinate geometry to three O2- atoms. There are one shorter (1.93 Å) and two longer (2.07 Å) Ni–O bond lengths. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to three Nb5+ atoms. In the second O2- site, O2- is bonded in a trigonal planar geometry to three Nb5+ atoms. In the third O2- site, O2- is bonded in a 2-coordinate geometry to one Nb5+, one Ni2+, and one O2- atom. The O–O bond length is 1.39 Å. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to two Nb5+ and one Ni2+ atom. In the fifth O2- site, O2- is bonded in a 2-coordinate geometry to one Nb5+ and one O2- atom.