Optical excitations of Si by time-dependent density-functional theory based on the exact-exchange Kohn-Sham band structure

Preprint

13 February 2002

preprint
Published by arXiv in arXiv

https://doi.org/10.48550/arXiv.cond-mat/0202214

Abstract

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.

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Version 1, 2002-02-13, ArXiv
Published version: International Journal of Quantum Chemistry, 91 (2), 257.

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