Materials Data on Na8TiO6 by Materials Project

Abstract

Na8TiO6 crystallizes in the orthorhombic Pna2_1 space group. The structure is three-dimensional. there are eight inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a distorted trigonal planar geometry to three O2- atoms. There are a spread of Na–O bond distances ranging from 2.25–2.32 Å. In the second Na1+ site, Na1+ is bonded to four O2- atoms to form distorted NaO4 tetrahedra that share corners with two equivalent TiO4 tetrahedra and corners with eight NaO4 tetrahedra. There are a spread of Na–O bond distances ranging from 2.28–2.54 Å. In the third Na1+ site, Na1+ is bonded in a 3-coordinate geometry to three O2- atoms. There are a spread of Na–O bond distances ranging from 2.27–2.37 Å. In the fourth Na1+ site, Na1+ is bonded in a 3-coordinate geometry to three O2- atoms. There are one shorter (2.32 Å) and two longer (2.34 Å) Na–O bond lengths. In the fifth Na1+ site, Na1+ is bonded to four O2- atoms to form NaO4 tetrahedra that share corners with two equivalent TiO4 tetrahedra, corners with four NaO4 tetrahedra, and edges with two NaO4 tetrahedra. There are a spread of Na–O bond distances ranging from 2.31–2.49 Å. In the sixth Na1+ site, Na1+ is bonded to four O2- atoms to form NaO4 tetrahedra that share corners with two equivalent TiO4 tetrahedra, corners with seven NaO4 tetrahedra, and an edgeedge with one NaO4 tetrahedra. There are a spread of Na–O bond distances ranging from 2.32–2.52 Å. In the seventh Na1+ site, Na1+ is bonded to four O2- atoms to form NaO4 tetrahedra that share corners with two equivalent TiO4 tetrahedra, corners with seven NaO4 tetrahedra, and an edgeedge with one NaO4 tetrahedra. There are a spread of Na–O bond distances ranging from 2.37–2.56 Å. In the eighth Na1+ site, Na1+ is bonded in a 3-coordinate geometry to three O2- atoms. There are a spread of Na–O bond distances ranging from 2.28–2.43 Å. Ti4+ is bonded to four O2- atoms to form TiO4 tetrahedra that share corners with eight NaO4 tetrahedra. There are a spread of Ti–O bond distances ranging from 1.83–1.86 Å. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded to four Na1+ and one Ti4+ atom to form distorted ONa4Ti trigonal bipyramids that share corners with two equivalent ONa3Ti tetrahedra and corners with two equivalent ONa4Ti trigonal bipyramids. In the second O2- site, O2- is bonded in a 5-coordinate geometry to four Na1+ and one Ti4+ atom. In the third O2- site, O2- is bonded in a 7-coordinate geometry to seven Na1+ atoms. In the fourth O2- site, O2- is bonded in a 6-coordinate geometry to six Na1+ atoms. In the fifth O2- site, O2- is bonded to three Na1+ and one Ti4+ atom to form distorted corner-sharing ONa3Ti tetrahedra. In the sixth O2- site, O2- is bonded to four Na1+ and one Ti4+ atom to form distorted ONa4Ti trigonal bipyramids that share corners with two equivalent ONa3Ti tetrahedra and corners with two equivalent ONa4Ti trigonal bipyramids.