Materials Data on Na2Ti9O19 by Materials Project
Na2Ti9O19 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Na1+ is bonded in a 5-coordinate geometry to seven O2- atoms. There are a spread of Na–O bond distances ranging from 2.22–2.76 Å. There are five inequivalent Ti4+ sites. In the first Ti4+ site, Ti4+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Ti–O bond distances ranging from 1.78–2.32 Å. In the second Ti4+ site, Ti4+ is bonded to six O2- atoms to form a mixture of distorted edge and corner-sharing TiO6 octahedra. The corner-sharing octahedra tilt angles range from 29–41°. There are a spread of Ti–O bond distances ranging from 1.85–2.17 Å. In the third Ti4+ site, Ti4+ is bonded to six O2- atoms to form a mixture of distorted edge and corner-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles are 28°. There are a spread of Ti–O bond distances ranging from 1.86–2.15 Å. In the fourth Ti4+ site, Ti4+ is bonded to six O2- atoms to form a mixture of distorted edge and corner-sharing TiO6 octahedra. The corner-sharing octahedra tilt angles range from 31–39°. There are a spread of Ti–O bond distances ranging from 1.81–2.31 Å. In the fifth Ti4+ site, Ti4+ is bonded to six O2- atoms to form corner-sharing TiO6 octahedra. The corner-sharing octahedra tilt angles range from 0–41°. There are a spread of Ti–O bond distances ranging from 1.90–2.04 Å. There are ten inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to three equivalent Na1+ and two Ti4+ atoms. In the second O2- site, O2- is bonded to four Ti4+ atoms to form a mixture of distorted edge and corner-sharing OTi4 trigonal pyramids. In the third O2- site, O2- is bonded in a square co-planar geometry to two equivalent Na1+ and two equivalent Ti4+ atoms. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to three Ti4+ atoms. In the fifth O2- site, O2- is bonded to four Ti4+ atoms to form a mixture of distorted edge and corner-sharing OTi4 trigonal pyramids. In the sixth O2- site, O2- is bonded in a linear geometry to two Ti4+ atoms. In the seventh O2- site, O2- is bonded in a 3-coordinate geometry to three Ti4+ atoms. In the eighth O2- site, O2- is bonded in a distorted T-shaped geometry to three Ti4+ atoms. In the ninth O2- site, O2- is bonded in a 4-coordinate geometry to three equivalent Na1+ and two Ti4+ atoms. In the tenth O2- site, O2- is bonded in a 3-coordinate geometry to three Ti4+ atoms.