DOE OSTI2020
Te4Nb2O13 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are four inequivalent Nb5+ sites. In the first Nb5+ site, Nb5+ is bonded to six O2- atoms to form corner-sharing NbO6 octahedra. The corner-sharing octahedra tilt angles range from 29–30°. There are a spread of Nb–O bond distances ranging from 1.84–2.15 Å. In the second Nb5+ site, Nb5+ is bonded to six O2- atoms to form corner-sharing NbO6 octahedra. The corner-sharing octahedra tilt angles range from 29–31°. There are a spread of Nb–O bond distances ranging from 1.84–2.16 Å. In the third Nb5+ site, Nb5+ is bonded to six O2- atoms to form corner-sharing NbO6 octahedra. The corner-sharing octahedra tilt angles range from 29–30°. There are a spread of Nb–O bond distances ranging from 1.84–2.15 Å. In the fourth Nb5+ site, Nb5+ is bonded to six O2- atoms to form corner-sharing NbO6 octahedra. The corner-sharing octahedra tilt angles range from 29–31°. There are a spread of Nb–O bond distances ranging from 1.84–2.16 Å. There are eight inequivalent Te4+ sites. In the first Te4+ site, Te4+ is bonded in a distorted rectangular see-saw-like geometry to four O2- atoms. There are a spread of Te–O bond distances ranging from 1.89–2.23 Å. In the second Te4+ site, Te4+ is bonded in a distorted rectangular see-saw-like geometry to four O2- atoms. There are a spread of Te–O bond distances ranging from 1.90–2.27 Å. In the third Te4+ site, Te4+ is bonded in a 3-coordinate geometry to four O2- atoms. There are a spread of Te–O bond distances ranging from 1.92–2.52 Å. In the fourth Te4+ site, Te4+ is bonded in a 3-coordinate geometry to three O2- atoms. There is one shorter (1.89 Å) and two longer (1.93 Å) Te–O bond length. In the fifth Te4+ site, Te4+ is bonded in a 4-coordinate geometry to four O2- atoms. There are a spread of Te–O bond distances ranging from 1.90–2.61 Å. In the sixth Te4+ site, Te4+ is bonded in a 4-coordinate geometry to four O2- atoms. There are a spread of Te–O bond distances ranging from 1.89–2.48 Å. In the seventh Te4+ site, Te4+ is bonded in a 4-coordinate geometry to four O2- atoms. There are a spread of Te–O bond distances ranging from 1.92–2.40 Å. In the eighth Te4+ site, Te4+ is bonded in a 3-coordinate geometry to three O2- atoms. There are a spread of Te–O bond distances ranging from 1.88–1.93 Å. There are twenty-six inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 150 degrees geometry to one Nb5+ and one Te4+ atom. In the second O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Te4+ atoms. In the third O2- site, O2- is bonded in a linear geometry to one Nb5+ and one Te4+ atom. In the fourth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Nb5+ and one Te4+ atom. In the fifth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Nb5+ and one Te4+ atom. In the sixth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Nb5+ and one Te4+ atom. In the seventh O2- site, O2- is bonded in a bent 120 degrees geometry to one Nb5+ and one Te4+ atom. In the eighth O2- site, O2- is bonded in a bent 150 degrees geometry to one Nb5+ and one Te4+ atom. In the ninth O2- site, O2- is bonded in a bent 150 degrees geometry to two Nb5+ atoms. In the tenth O2- site, O2- is bonded in a bent 120 degrees geometry to one Nb5+ and one Te4+ atom. In the eleventh O2- site, O2- is bonded in a linear geometry to one Nb5+ and one Te4+ atom. In the twelfth O2- site, O2- is bonded in a bent 150 degrees geometry to two Nb5+ atoms. In the thirteenth O2- site, O2- is bonded in a bent 150 degrees geometry to two Nb5+ atoms. In the fourteenth O2- site, O2- is bonded in a bent 120 degrees geometry to one Nb5+ and one Te4+ atom. In the fifteenth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Nb5+ and one Te4+ atom. In the sixteenth O2- site, O2- is bonded in a bent 120 degrees geometry to two Te4+ atoms. In the seventeenth O2- site, O2- is bonded in a linear geometry to one Nb5+ and one Te4+ atom. In the eighteenth O2- site, O2- is bonded in a bent 150 degrees geometry to two Nb5+ atoms. In the nineteenth O2- site, O2- is bonded in a 1-coordinate geometry to three Te4+ atoms. In the twentieth O2- site, O2- is bonded in a bent 120 degrees geometry to one Nb5+ and one Te4+ atom. In the twenty-first O2- site, O2- is bonded in a distorted water-like geometry to two Te4+ atoms. In the twenty-second O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Nb5+ and one Te4+ atom. In the twenty-third O2- site, O2- is bonded in a bent 120 degrees geometry to two Te4+ atoms. In the twenty-fourth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Nb5+ and one Te4+ atom. In the twenty-fifth O2- site, O2- is bonded in a 1-coordinate geometry to three Te4+ atoms. In the twenty-sixth O2- site, O2- is bonded in a linear geometry to one Nb5+ and one Te4+ atom.