Materials Data on Na2TiSi4O11 by Materials Project
Na2TiSi4O11 crystallizes in the tetragonal I4/m space group. The structure is three-dimensional. Na1+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Na–O bond distances ranging from 2.38–2.71 Å. Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with two equivalent TiO6 octahedra and corners with four equivalent SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 0°. There is one shorter (1.93 Å) and five longer (2.02 Å) Ti–O bond length. Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one TiO6 octahedra and corners with three equivalent SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 41°. There are a spread of Si–O bond distances ranging from 1.60–1.65 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 150 degrees geometry to two equivalent Si4+ atoms. In the second O2- site, O2- is bonded in an octahedral geometry to four equivalent Na1+ and two equivalent Ti4+ atoms. In the third O2- site, O2- is bonded in a linear geometry to two equivalent Ti4+ atoms. In the fourth O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Na1+, one Ti4+, and one Si4+ atom. In the fifth O2- site, O2- is bonded in a 2-coordinate geometry to one Na1+ and two equivalent Si4+ atoms.