Materials Data on Na4Ti11O24 by Materials Project
Na4Ti11O24 is beta indium sulfide-derived structured and crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are three inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to four O2- atoms to form NaO4 tetrahedra that share corners with eleven TiO6 octahedra. The corner-sharing octahedra tilt angles range from 50–69°. There are one shorter (2.17 Å) and three longer (2.19 Å) Na–O bond lengths. 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 2.25–2.54 Å. In the third Na1+ site, Na1+ is bonded to four O2- atoms to form NaO4 tetrahedra that share corners with eleven TiO6 octahedra. The corner-sharing octahedra tilt angles range from 53–71°. There are a spread of Na–O bond distances ranging from 2.14–2.17 Å. There are six inequivalent Ti4+ sites. In the first Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with three NaO4 tetrahedra and edges with four TiO6 octahedra. There are a spread of Ti–O bond distances ranging from 1.93–2.05 Å. In the second Ti4+ site, Ti4+ is bonded to six O2- atoms to form distorted TiO6 octahedra that share corners with three NaO4 tetrahedra and edges with five TiO6 octahedra. There are a spread of Ti–O bond distances ranging from 1.83–2.20 Å. In the third Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with three equivalent NaO4 tetrahedra and edges with six TiO6 octahedra. There are a spread of Ti–O bond distances ranging from 1.98–2.01 Å. In the fourth Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with three NaO4 tetrahedra and edges with six TiO6 octahedra. There are a spread of Ti–O bond distances ranging from 1.92–2.11 Å. In the fifth Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with three NaO4 tetrahedra and edges with six TiO6 octahedra. There are a spread of Ti–O bond distances ranging from 1.98–2.03 Å. In the sixth Ti4+ site, Ti4+ is bonded to six O2- atoms to form distorted TiO6 octahedra that share corners with three NaO4 tetrahedra and edges with five TiO6 octahedra. There are a spread of Ti–O bond distances ranging from 1.84–2.18 Å. There are fourteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Na1+ and three Ti4+ atoms. In the second O2- site, O2- is bonded in a distorted T-shaped geometry to three Ti4+ atoms. In the third O2- site, O2- is bonded to two Na1+ and two Ti4+ atoms to form distorted ONa2Ti2 trigonal pyramids that share corners with three ONaTi3 tetrahedra and edges with two ONa2Ti2 trigonal pyramids. 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 one Na1+ and three Ti4+ atoms to form distorted ONaTi3 tetrahedra that share corners with two ONaTi3 tetrahedra, a cornercorner with one ONa2Ti2 trigonal pyramid, and edges with three ONaTi3 tetrahedra. In the sixth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to three Ti4+ atoms. In the seventh O2- site, O2- is bonded to two Na1+ and two equivalent Ti4+ atoms to form distorted ONa2Ti2 trigonal pyramids that share corners with two equivalent ONaTi3 tetrahedra and edges with two equivalent ONa2Ti2 trigonal pyramids. In the eighth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to three Ti4+ atoms. In the ninth O2- site, O2- is bonded to one Na1+ and three Ti4+ atoms to form distorted ONaTi3 tetrahedra that share corners with two ONaTi3 tetrahedra, a cornercorner with one ONa2Ti2 trigonal pyramid, and edges with three ONaTi3 tetrahedra. In the tenth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to three Ti4+ atoms. In the eleventh O2- site, O2- is bonded to one Na1+ and three Ti4+ atoms to form ONaTi3 tetrahedra that share corners with two ONaTi3 tetrahedra, a cornercorner with one ONa2Ti2 trigonal pyramid, and edges with three ONaTi3 tetrahedra. In the twelfth O2- site, O2- is bonded in a 2-coordinate geometry to one Na1+ and two equivalent Ti4+ atoms. In the thirteenth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to one Na1+ and two Ti4+ atoms. In the fourteenth O2- site, O2- is bonded to one Na1+ and three Ti4+ atoms to form distorted ONaTi3 tetrahedra that share a cornercorner with one ONaTi3 tetrahedra, a cornercorner with one ONa2Ti2 trigonal pyramid, and edges with three ONaTi3 tetrahedra.