DOE OSTI2020
Cs2Nb4O11 crystallizes in the orthorhombic Pnn2 space group. The structure is three-dimensional. there are four inequivalent Cs1+ sites. In the first Cs1+ site, Cs1+ is bonded in a 2-coordinate geometry to seven O2- atoms. There are a spread of Cs–O bond distances ranging from 2.99–3.47 Å. In the second Cs1+ site, Cs1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Cs–O bond distances ranging from 3.19–3.65 Å. In the third Cs1+ site, Cs1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Cs–O bond distances ranging from 3.21–3.64 Å. In the fourth Cs1+ site, Cs1+ is bonded in a 2-coordinate geometry to seven O2- atoms. There are a spread of Cs–O bond distances ranging from 2.99–3.46 Å. There are nine 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 35–45°. There are a spread of Nb–O bond distances ranging from 1.88–2.17 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 35–43°. There are a spread of Nb–O bond distances ranging from 1.96–2.05 Å. In the third Nb5+ site, Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with five NbO6 octahedra and a cornercorner with one NbO4 tetrahedra. The corner-sharing octahedra tilt angles range from 29–45°. There are a spread of Nb–O bond distances ranging from 1.89–2.27 Å. In the fourth Nb5+ site, Nb5+ is bonded to four O2- atoms to form corner-sharing NbO4 tetrahedra. The corner-sharing octahedra tilt angles range from 53–62°. There is two shorter (1.86 Å) and two longer (1.91 Å) Nb–O bond length. In the fifth Nb5+ site, Nb5+ is bonded to six O2- atoms to form corner-sharing NbO6 octahedra. The corner-sharing octahedra tilt angles range from 35–45°. There are a spread of Nb–O bond distances ranging from 1.88–2.17 Å. In the sixth Nb5+ site, Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with five NbO6 octahedra and a cornercorner with one NbO4 tetrahedra. The corner-sharing octahedra tilt angles range from 29–45°. There are a spread of Nb–O bond distances ranging from 1.89–2.28 Å. In the seventh Nb5+ site, Nb5+ is bonded to six O2- atoms to form distorted NbO6 octahedra that share corners with four NbO6 octahedra, corners with two NbO4 tetrahedra, and an edgeedge with one NbO6 octahedra. The corner-sharing octahedra tilt angles range from 29–34°. There are a spread of Nb–O bond distances ranging from 1.88–2.29 Å. In the eighth Nb5+ site, Nb5+ is bonded to four O2- atoms to form corner-sharing NbO4 tetrahedra. The corner-sharing octahedra tilt angles range from 53–62°. There is two shorter (1.86 Å) and two longer (1.91 Å) Nb–O bond length. In the ninth Nb5+ site, Nb5+ is bonded to six O2- atoms to form distorted NbO6 octahedra that share corners with four NbO6 octahedra, corners with two NbO4 tetrahedra, and an edgeedge with one NbO6 octahedra. The corner-sharing octahedra tilt angles range from 29–34°. There are a spread of Nb–O bond distances ranging from 1.87–2.29 Å. There are twenty-two inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to one Cs1+ and two Nb5+ atoms. In the second O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to three Nb5+ atoms. In the third O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Cs1+ and two Nb5+ atoms. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to one Cs1+ and two Nb5+ atoms. In the fifth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Cs1+ and two Nb5+ atoms. In the sixth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to three Nb5+ atoms. In the seventh O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Cs1+ and two Nb5+ atoms. In the eighth O2- site, O2- is bonded in a bent 150 degrees geometry to one Cs1+ and two Nb5+ atoms. In the ninth O2- site, O2- is bonded in a 2-coordinate geometry to one Cs1+ and two Nb5+ atoms. In the tenth O2- site, O2- is bonded in a 3-coordinate geometry to one Cs1+ and two Nb5+ atoms. In the eleventh O2- site, O2- is bonded in a bent 150 degrees geometry to one Cs1+ and two Nb5+ atoms. In the twelfth O2- site, O2- is bonded in a bent 150 degrees geometry to two Cs1+ and two Nb5+ atoms. In the thirteenth O2- site, O2- is bonded in a bent 150 degrees geometry to two Cs1+ and two Nb5+ atoms. In the fourteenth O2- site, O2- is bonded in a 2-coordinate geometry to one Cs1+ and two Nb5+ atoms. In the fifteenth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Cs1+ and two Nb5+ atoms. In the sixteenth O2- site, O2- is bonded in a 2-coordinate geometry to two Cs1+ and two Nb5+ atoms. In the seventeenth O2- site, O2- is bonded in a 2-coordinate geometry to two Cs1+ and two Nb5+ atoms. In the eighteenth O2- site, O2- is bonded in a 2-coordinate geometry to one Cs1+ and two Nb5+ atoms. In the nineteenth O2- site, O2- is bonded in a 2-coordinate geometry to one Cs1+ and two Nb5+ atoms. In the twentieth O2- site, O2- is bonded in a 2-coordinate geometry to one Cs1+ and two Nb5+ atoms. In the twenty-first O2- site, O2- is bonded in a bent 150 degrees geometry to two Cs1+ and two Nb5+ atoms. In the twenty-second O2- site, O2- is bonded in a bent 150 degrees geometry to two Cs1+ and two Nb5+ atoms.