Figure 7

Density Functional Calculations for Na2TiO3. (a) Optimized structures of Na16Ti8O24, Na12Ti8O24, Na8Ti8O24, Na4Ti8O24 and Ti8O24 from left to right. (b) Mulliken and (c) Electron populations of the valence orbital of each element in Na16Ti8O24, Na12Ti8O24, Na8Ti8O24, Na4Ti8O24 and Ti8O24 which corresponds x = 2, 1.5, 1, 0.5, 0 in NaxTiO3 respectively. The lines connect average populations of each orbitals in different concentrations. The magenta triangles show average populations of 2p orbitals of different types of oxygen atoms at each concentration.