DOI: 10.17188/1291760
title: Materials Data on Na4Ti7O16 by Materials Project

description: Na4Ti7O16 crystallizes in the monoclinic Pm space group. The structure is three-dimensional. there are three inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 4-coordinate geometry to four O2- atoms. There are a spread of Na–O bond distances ranging from 2.11–2.46 Å. In the second Na1+ site, Na1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Na–O bond distances ranging from 2.20–2.41 Å. In the third Na1+ site, Na1+ is bonded in a 4-coordinate geometry to five O2- atoms. There are a spread of Na–O bond distances ranging from 2.14–2.78 Å. There are five inequivalent Ti4+ sites. In the first Ti4+ site, Ti4+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing TiO6 octahedra. The corner-sharing octahedra tilt angles range from 46–48°. There are a spread of Ti–O bond distances ranging from 1.92–2.08 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 48–53°. There are a spread of Ti–O bond distances ranging from 1.90–2.10 Å. In the third 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 1.93–2.34 Å. In the fourth Ti4+ site, Ti4+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing TiO6 octahedra. The corner-sharing octahedra tilt angles range from 46–53°. There are a spread of Ti–O bond distances ranging from 1.88–2.20 Å. In the fifth Ti4+ site, Ti4+ is bonded to six O2- atoms to form edge-sharing TiO6 octahedra. There are a spread of Ti–O bond distances ranging from 1.86–2.18 Å. There are twelve inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to three Ti4+ atoms. In the second O2- site, O2- is bonded in a 4-coordinate geometry to four Na1+ and two equivalent Ti4+ atoms. In the third O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Na1+ and three Ti4+ atoms. In the fourth O2- site, O2- is bonded to two Na1+ and two Ti4+ atoms to form distorted ONa2Ti2 trigonal pyramids that share corners with two ONa2Ti3 square pyramids, corners with two equivalent ONa2Ti2 trigonal pyramids, and edges with two ONa2Ti3 square pyramids. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to three Ti4+ atoms. In the sixth O2- site, O2- is bonded in a distorted trigonal planar geometry to three Ti4+ atoms. In the seventh O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two Na1+ and two Ti4+ atoms. In the eighth O2- site, O2- is bonded to two equivalent Na1+ and three Ti4+ atoms to form distorted ONa2Ti3 square pyramids that share corners with two equivalent ONa2Ti2 trigonal pyramids, edges with two equivalent ONa3Ti2 square pyramids, and edges with two equivalent ONa2Ti2 trigonal pyramids. In the ninth O2- site, O2- is bonded to three Na1+ and two equivalent Ti4+ atoms to form distorted ONa3Ti2 square pyramids that share corners with two equivalent ONa2Ti2 trigonal pyramids, edges with two equivalent ONa2Ti3 square pyramids, and edges with two equivalent ONa2Ti2 trigonal pyramids. In the tenth O2- site, O2- is bonded in a tetrahedral geometry to one Na1+ and three Ti4+ atoms. In the eleventh O2- site, O2- is bonded in a trigonal non-coplanar geometry to three Ti4+ atoms. In the twelfth O2- site, O2- is bonded in a 3-coordinate geometry to three Ti4+ atoms.