Materials Data on Nb9AsO25 by Materials Project

Nb9AsO25 crystallizes in the monoclinic C2 space group. The structure is three-dimensional. there are five inequivalent Nb5+ sites. In the first Nb5+ site, Nb5+ is bonded to six O2- atoms to form a mixture of distorted edge and corner-sharing NbO6 octahedra. The corner-sharing octahedra tilt angles range from 4–31°. There are a spread of Nb–O bond distances ranging from 1.86–2.30 Å. In the second Nb5+ site, Nb5+ is bonded to six O2- atoms to form a mixture of distorted edge and corner-sharing NbO6 octahedra. The corner-sharing octahedra tilt angles range from 4–31°. There are a spread of Nb–O bond distances ranging from 1.86–2.30 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 0–7°. There are a spread of Nb–O bond distances ranging from 1.83–2.05 Å. In the fourth Nb5+ site, Nb5+ is bonded to six O2- atoms to form distorted NbO6 octahedra that share corners with four NbO6 octahedra, a cornercorner with one AsO4 tetrahedra, and edges with two equivalent NbO6 octahedra. The corner-sharing octahedra tilt angles range from 4–32°. There are a spread of Nb–O bond distances ranging from 1.81–2.35 Å. In the fifth Nb5+ site, Nb5+ is bonded to six O2- atoms to form distorted NbO6 octahedra that share corners with four NbO6 octahedra, a cornercorner with one AsO4 tetrahedra, and edges with two equivalent NbO6 octahedra. The corner-sharing octahedra tilt angles range from 4–32°. There are a spread of Nb–O bond distances ranging from 1.81–2.35 Å. As5+ is bonded to four equivalent O2- atoms to form AsO4 tetrahedra that share corners with four NbO6 octahedra. The corner-sharing octahedral tilt angles are 46°. All As–O bond lengths are 1.72 Å. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded in a linear geometry to two Nb5+ atoms. 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 3-coordinate geometry to three Nb5+ atoms. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to three Nb5+ atoms. In the fifth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Nb5+ and one As5+ atom. In the sixth O2- site, O2- is bonded in a linear geometry to two Nb5+ atoms. In the seventh O2- site, O2- is bonded in a linear geometry to two equivalent 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 Nb5+ atoms.