Optical excitations of Si by time-dependent density-functional theory   based on the exact-exchange Kohn-Sham band structure
  We calculate the imaginary part of the frequency-dependent dielectric function of bulk silicon by applying time-dependent density-functional theory based on the exact-exchange (EXX) Kohn-Sham (KS) band structure and the adiabatic local-density approximation (ALDA) kernel. The position of the E2 absorption peak calculated with the EXX band structure at the independent-particle level is in excellent agreement with experiments, which demonstrates the good quality of EXX `KS quasiparticles'. The excitonic E1 peak that is missing at the independent-particle level remains absent if two-particle interaction effects are taken into account within the time-dependent LDA, demonstrating the incapability of the ALDA kernel to describe excitonic effects. 
Yong-Hoon Kim (1), Martin Staedele (2), and Andreas Goerling (1) ((1)   Theoretische Chemie, TU Muenchen (2) Infineon Techno...