Electronic and optical properties of BaTiO3 and SrTiO3

We have used the linear muffin-tin-orbital method, without geometrical approximations, to calculate the electronic structure of tetragonal BaTiO3 and cubic SrTiO3. Using our self-consistent potential, we have calculated the frequency-dependent dielectric function and the reflectivity spectrum. For tetragonal BaTiO3 the anisotropic optical properties are calculated. We compare our calculations with experimental data and find good agreement. We analyze the origin of the different calculated features in the optical spectra by means of our energy-band structure. (C) 2001 American Institute of Physics.