DOE OSTI2020
BiNbO4 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are two 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 25–40°. There are a spread of Nb–O bond distances ranging from 1.87–2.25 Å. In the second Nb5+ site, Nb5+ is bonded to six O2- atoms to form distorted corner-sharing NbO6 octahedra. The corner-sharing octahedra tilt angles range from 25–40°. There are a spread of Nb–O bond distances ranging from 1.87–2.28 Å. There are two inequivalent Bi3+ sites. In the first Bi3+ site, Bi3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Bi–O bond distances ranging from 2.24–3.08 Å. In the second Bi3+ site, Bi3+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Bi–O bond distances ranging from 2.22–2.99 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to one Nb5+ and three Bi3+ atoms. In the second O2- site, O2- is bonded in a 2-coordinate geometry to two Nb5+ and one Bi3+ atom. In the third O2- site, O2- is bonded in a 1-coordinate geometry to two Nb5+ and one Bi3+ atom. In the fourth O2- site, O2- is bonded in a 4-coordinate geometry to one Nb5+ and three Bi3+ atoms. In the fifth O2- site, O2- is bonded in a bent 150 degrees geometry to two Nb5+ and one Bi3+ atom. In the sixth O2- site, O2- is bonded in a 3-coordinate geometry to one Nb5+ and three Bi3+ atoms. In the seventh O2- site, O2- is bonded in a distorted trigonal planar geometry to one Nb5+ and two Bi3+ atoms. In the eighth O2- site, O2- is bonded in a 1-coordinate geometry to two Nb5+ and one Bi3+ atom.