Optical absorption spectra of metal oxides from time-dependent density functional theory and many-body perturbation theory based on optimally-tuned hybrid functionals

TL;DR

This study compares TDDFT and GW-BSE methods using optimally-tuned hybrid functionals to accurately predict optical spectra of various metal oxides, achieving high agreement with experimental data.

Contribution

It demonstrates that both TDDFT and GW-BSE approaches with non-empirical hybrid functionals can reliably compute optical properties of complex metal oxides.

Findings

Mean absolute error less than 0.4 eV in predictions

Excellent agreement with experimental spectra for all studied oxides

Effective for challenging materials like Cu2O and ZnO

Abstract

Using both time-dependent density functional theory (TDDFT) and the ``single-shot" $GW$ plus Bethe-Salpeter equation ($GW$-BSE) approach, we compute optical band gaps and optical absorption spectra from first principles for eight common binary and ternary closed-shell metal oxides (MgO, Al$_2$O$_3$, CaO, TiO$_2$, Cu$_2$O, ZnO, BaSnO$_3$, and BiVO$_4$), based on the non-empirical Wannier-localized optimally-tuned screened range-separated hybrid functional. Overall, we find excellent agreement between our TDDFT and $GW$-BSE results and experiment, with a mean absolute error less than 0.4 eV, including for Cu$_2$O and ZnO, traditionally considered to be challenging for both methods.