Dielectric properties and excitons for extended systems from hybrid functionals

We have calculated static and dynamic response properties for several semiconducting and insulating solids using hybrid functionals, which admix a small fraction of nonlocal Fock exchange to an otherwise semilocal density functional. The calculated static and dynamic properties are clearly improved compared to conventional semilocal density functionals; in particular the oscillator strength at low energy excitations is well described.

Figure 1

(Color online) Optical-absorption spectra for Si, GaAs, SiC, C, and LiF using TD-HSE $\left(\mu =0.3{\text{Å}}^{-1}\right)$ in the independent-particle approximation (dashed black line) and including electron-hole interactions [full red (dark gray) line]. TD-HSE06 results $\left(\mu =0.2{\text{Å}}^{-1}\right)$ are shown using the blue (light gray) line, and experiments are shown by dots [Si (Ref. 25), GaAs (Ref. 26), SiC (Ref. 27), C (Ref. 28), and LiF (Ref. 29)].