DOI: 10.17188/1719303
title: Materials Data on NbFeNi(O2F)2 by Materials Project

description: NbFeNi(O2F)2 is beta Vanadium nitride-derived structured and crystallizes in the monoclinic Pm 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 four equivalent FeO6 octahedra, corners with four equivalent NiO3F3 octahedra, and edges with two equivalent NbO6 octahedra. The corner-sharing octahedra tilt angles range from 49–52°. There are a spread of Nb–O bond distances ranging from 1.89–2.13 Å. In the second Nb5+ site, Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with eight FeO6 octahedra and edges with two equivalent NbO6 octahedra. The corner-sharing octahedra tilt angles range from 47–53°. There are a spread of Nb–O bond distances ranging from 1.90–2.13 Å. There are two inequivalent Fe3+ sites. In the first Fe3+ site, Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with eight NbO6 octahedra and edges with two equivalent FeO6 octahedra. The corner-sharing octahedra tilt angles range from 47–52°. There are a spread of Fe–O bond distances ranging from 1.96–2.15 Å. In the second Fe3+ site, Fe3+ is bonded to three O2- and three F1- atoms to form FeO3F3 octahedra that share corners with four equivalent NbO6 octahedra, corners with four equivalent NiF6 octahedra, and edges with two equivalent FeO3F3 octahedra. The corner-sharing octahedra tilt angles range from 47–53°. There is two shorter (1.94 Å) and one longer (2.01 Å) Fe–O bond length. There are one shorter (2.08 Å) and two longer (2.12 Å) Fe–F bond lengths. There are two inequivalent Ni2+ sites. In the first Ni2+ site, Ni2+ is bonded to three O2- and three F1- atoms to form NiO3F3 octahedra that share corners with four equivalent NbO6 octahedra, corners with four equivalent NiF6 octahedra, and edges with two equivalent NiO3F3 octahedra. The corner-sharing octahedra tilt angles range from 48–51°. There are two shorter (2.02 Å) and one longer (2.07 Å) Ni–O bond lengths. There are two shorter (2.08 Å) and one longer (2.12 Å) Ni–F bond lengths. In the second Ni2+ site, Ni2+ is bonded to six F1- atoms to form NiF6 octahedra that share corners with four equivalent FeO3F3 octahedra, corners with four equivalent NiO3F3 octahedra, and edges with two equivalent NiF6 octahedra. The corner-sharing octahedra tilt angles range from 47–51°. There are a spread of Ni–F bond distances ranging from 1.99–2.09 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Nb5+ and one Ni2+ atom. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Nb5+ and one Fe3+ atom. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Nb5+ and one Fe3+ atom. In the fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Nb5+ and one Fe3+ atom. In the fifth O2- site, O2- is bonded in a trigonal planar geometry to one Nb5+ and two equivalent Fe3+ atoms. In the sixth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Nb5+ and two equivalent Ni2+ atoms. In the seventh O2- site, O2- is bonded in a trigonal planar geometry to one Nb5+ and two equivalent Fe3+ atoms. In the eighth O2- site, O2- is bonded in a 3-coordinate geometry to one Nb5+ and two equivalent Fe3+ atoms. There are four inequivalent F1- sites. In the first F1- site, F1- is bonded in a distorted trigonal planar geometry to one Fe3+ and two equivalent Ni2+ atoms. In the second F1- site, F1- is bonded in a distorted trigonal planar geometry to three Ni2+ atoms. In the third F1- site, F1- is bonded in a distorted trigonal planar geometry to three Ni2+ atoms. In the fourth F1- site, F1- is bonded in a 3-coordinate geometry to two equivalent Fe3+ and one Ni2+ atom.