Materials Data on NaNb2H7O9 by Materials Project
NaNb2H7O9 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Na1+ is bonded to five O2- atoms to form distorted corner-sharing NaO5 trigonal bipyramids. There are a spread of Na–O bond distances ranging from 2.35–2.46 Å. There are two 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 1.79–2.46 Å. In the second Nb5+ site, Nb5+ is bonded to six O2- atoms to form distorted edge-sharing NbO6 octahedra. There are a spread of Nb–O bond distances ranging from 1.85–2.29 Å. There are seven inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the second H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 1.00 Å. In the third H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 1.00 Å. In the fourth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the fifth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the sixth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the seventh H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 1.00 Å. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted water-like geometry to one Na1+ and two H1+ atoms. In the second O2- site, O2- is bonded in a water-like geometry to one Na1+ and two H1+ atoms. In the third O2- site, O2- is bonded in a bent 120 degrees geometry to two Nb5+ atoms. In the fourth O2- site, O2- is bonded in a distorted water-like geometry to two equivalent Na1+ and two H1+ atoms. In the fifth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two Nb5+ atoms. In the sixth O2- site, O2- is bonded in a distorted single-bond geometry to three Nb5+ and one H1+ atom. In the seventh O2- site, O2- is bonded in a linear geometry to 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 distorted bent 150 degrees geometry to one Na1+ and one Nb5+ atom.