Optical properties of IT and 2H phases of TsS_2 and TaSe_2

摘要

We have calculated the anisotropic frequency dependent dielectric function for the iT and 2H phases of TaS_2 using the linear muffin tin orbital method within the atomic sphere approximation. We find significant anisotropy in the frequency dependent dielectiric function for the lT and 2H phases at low energies (less than 4 eV). Unfortunately there are no experimental data to compare with. The averaged dielectric function agrees with the available experimental data except that the calculated peak heights are underestimated and shifted to higher energies by 1-2eV.