DOE OSTI2020
TiNbO4 is beta Vanadium nitride-derived structured and crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are three inequivalent Ti4+ sites. In the first Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with two equivalent TiO6 octahedra, corners with six NbO6 octahedra, an edgeedge with one TiO6 octahedra, and an edgeedge with one NbO6 octahedra. The corner-sharing octahedra tilt angles range from 44–50°. There are a spread of Ti–O bond distances ranging from 1.97–2.06 Å. In the second Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with three equivalent NbO6 octahedra, corners with five TiO6 octahedra, and edges with two NbO6 octahedra. The corner-sharing octahedra tilt angles range from 44–52°. There are a spread of Ti–O bond distances ranging from 1.97–2.05 Å. In the third Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with three equivalent TiO6 octahedra, corners with five NbO6 octahedra, an edgeedge with one TiO6 octahedra, and an edgeedge with one NbO6 octahedra. The corner-sharing octahedra tilt angles range from 44–51°. There are a spread of Ti–O bond distances ranging from 1.93–2.06 Å. There are three inequivalent Nb4+ sites. In the first Nb4+ site, Nb4+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with two equivalent NbO6 octahedra, corners with six TiO6 octahedra, an edgeedge with one TiO6 octahedra, and an edgeedge with one NbO6 octahedra. The corner-sharing octahedra tilt angles range from 45–53°. There are a spread of Nb–O bond distances ranging from 2.04–2.09 Å. In the second Nb4+ site, Nb4+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with three equivalent TiO6 octahedra, corners with five NbO6 octahedra, and edges with two TiO6 octahedra. The corner-sharing octahedra tilt angles range from 46–53°. There are a spread of Nb–O bond distances ranging from 1.99–2.08 Å. In the third Nb4+ site, Nb4+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with three equivalent NbO6 octahedra, corners with five TiO6 octahedra, an edgeedge with one TiO6 octahedra, and an edgeedge with one NbO6 octahedra. The corner-sharing octahedra tilt angles range from 44–51°. There are two shorter (2.03 Å) and four longer (2.06 Å) Nb–O bond lengths. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted T-shaped geometry to one Ti4+ and two Nb4+ atoms. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ti4+ and two Nb4+ atoms. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ti4+ and two Nb4+ atoms. In the fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to three Ti4+ atoms. In the fifth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ti4+ and two Nb4+ atoms. In the sixth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Ti4+ and one Nb4+ atom. In the seventh O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ti4+ and two Nb4+ atoms. In the eighth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Ti4+ and one Nb4+ atom. In the ninth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Ti4+ and one Nb4+ atom.