Materials Data on Na3Nb6O11 by Materials Project
Na3Nb6O11 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are four shorter (2.34 Å) and two longer (2.35 Å) Na–O bond lengths. In the second Na1+ site, Na1+ is bonded to four O2- atoms to form distorted NaO4 tetrahedra that share corners with nine NbO5 square pyramids. There are a spread of Na–O bond distances ranging from 2.25–2.34 Å. There are two inequivalent Nb+3.17+ sites. In the first Nb+3.17+ site, Nb+3.17+ is bonded to five O2- atoms to form NbO5 square pyramids that share corners with six NbO5 square pyramids, corners with three equivalent NaO4 tetrahedra, and edges with two NbO5 square pyramids. There are a spread of Nb–O bond distances ranging from 2.03–2.19 Å. In the second Nb+3.17+ site, Nb+3.17+ is bonded to five O2- atoms to form NbO5 square pyramids that share corners with six NbO5 square pyramids, corners with three equivalent NaO4 tetrahedra, and edges with two equivalent NbO5 square pyramids. There are a spread of Nb–O bond distances ranging from 2.02–2.19 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two Na1+ and two Nb+3.17+ atoms. In the second O2- site, O2- is bonded in a square co-planar geometry to four Nb+3.17+ atoms. In the third O2- site, O2- is bonded in a distorted tetrahedral geometry to one Na1+ and three Nb+3.17+ atoms. In the fourth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two Na1+ and two equivalent Nb+3.17+ atoms. In the fifth O2- site, O2- is bonded in a square co-planar geometry to four equivalent Nb+3.17+ atoms.