DOI: 10.17188/1291030
title: Materials Data on TiNb2O7 by Materials Project

description: TiNb2O7 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 in a 6-coordinate geometry to six O2- atoms. There are a spread of Ti–O bond distances ranging from 1.78–2.40 Å. In the second Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with two equivalent TiO6 octahedra and corners with two NbO6 octahedra. The corner-sharing octahedra tilt angles range from 1–10°. There are a spread of Ti–O bond distances ranging from 1.91–2.07 Å. In the third Ti4+ site, Ti4+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Ti–O bond distances ranging from 1.77–2.31 Å. There are six inequivalent Nb5+ sites. In the first Nb5+ site, Nb5+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Nb–O bond distances ranging from 1.80–2.42 Å. In the second Nb5+ site, Nb5+ is bonded to six O2- atoms to form distorted NbO6 octahedra that share a cornercorner with one TiO6 octahedra, corners with four NbO6 octahedra, and edges with two equivalent NbO6 octahedra. The corner-sharing octahedra tilt angles range from 3–32°. There are a spread of Nb–O bond distances ranging from 1.80–2.31 Å. In the third Nb5+ site, Nb5+ is bonded to six O2- atoms to form distorted corner-sharing NbO6 octahedra. The corner-sharing octahedra tilt angles range from 11–35°. There are a spread of Nb–O bond distances ranging from 1.83–2.28 Å. In the fourth Nb5+ site, Nb5+ is bonded to six O2- atoms to form distorted corner-sharing NbO6 octahedra. The corner-sharing octahedra tilt angles range from 3–29°. There are a spread of Nb–O bond distances ranging from 1.87–2.28 Å. In the fifth Nb5+ site, Nb5+ is bonded to six O2- atoms to form distorted NbO6 octahedra that share a cornercorner with one TiO6 octahedra, corners with two equivalent NbO6 octahedra, and edges with two equivalent NbO6 octahedra. The corner-sharing octahedra tilt angles range from 9–33°. There are a spread of Nb–O bond distances ranging from 1.81–2.33 Å. In the sixth Nb5+ site, Nb5+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Nb–O bond distances ranging from 1.80–2.46 Å. There are twenty-one inequivalent O2- sites. In the first O2- site, O2- is bonded in a linear geometry to one Ti4+ and one Nb5+ atom. In the second O2- site, O2- is bonded in a 3-coordinate geometry to three Nb5+ atoms. In the third O2- site, O2- is bonded in a linear geometry to one Ti4+ and one Nb5+ atom. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to one Ti4+ and two equivalent Nb5+ atoms. In the fifth O2- site, O2- is bonded in a linear geometry to one Ti4+ and one Nb5+ atom. In the sixth O2- site, O2- is bonded in a linear geometry to one Ti4+ and one Nb5+ atom. In the seventh O2- site, O2- is bonded in a 3-coordinate geometry to one Ti4+ and two Nb5+ atoms. In the eighth O2- site, O2- is bonded in a linear geometry to two Nb5+ atoms. In the ninth O2- site, O2- is bonded in a linear geometry to two equivalent Ti4+ atoms. In the tenth O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Ti4+ and two Nb5+ atoms. In the eleventh O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Ti4+ and one Nb5+ atom. In the twelfth O2- site, O2- is bonded in a 3-coordinate geometry to one Ti4+ and two equivalent Nb5+ atoms. In the thirteenth O2- site, O2- is bonded in a 4-coordinate geometry to one Ti4+ and three Nb5+ atoms. In the fourteenth O2- site, O2- is bonded in a linear geometry to one Ti4+ and one Nb5+ atom. In the fifteenth O2- site, O2- is bonded in a 3-coordinate geometry to one Ti4+ and two Nb5+ atoms. In the sixteenth O2- site, O2- is bonded in a linear geometry to two Nb5+ atoms. In the seventeenth O2- site, O2- is bonded in a linear geometry to one Ti4+ and one Nb5+ atom. In the eighteenth O2- site, O2- is bonded in a 3-coordinate geometry to three Nb5+ atoms. In the nineteenth O2- site, O2- is bonded in a linear geometry to two Nb5+ atoms. In the twentieth O2- site, O2- is bonded in a 3-coordinate geometry to three Nb5+ atoms. In the twenty-first O2- site, O2- is bonded in a linear geometry to one Ti4+ and one Nb5+ atom.