Dielectric-Dependent Hybrid XC Functionals in RT-TDDFT via the MLWF Gauge

A new class of hybrid exchange-correlation (XC) approximations, generally termed dielectric-dependent range-separated hybrid XC, has gained great attention over the last decade in the context of Density Functional Theory (DFT). Because of its significant computational cost, the use of these advanced XC functionals in the context of real-time time-dependent DFT (RT-TDDFT) has been limited. By utilizing the unitary transformation to the Maximally Localized Wannier function (MLWF) gauge so that the exact (Fock) exchange can be more efficiently computed for large complex systems(1), we employ and examine the performance of these advanced XC functionals. Using silicon carbide as an example, we compute the optical absorption spectra using dielectric-dependent global and range-separated hybrid functionals. The use of the MLWF gauge results in a significant speed-up for large simulations.

1. (1) C. Shepard, R. Zhou, J. Bost, T. E. Carney, Y.Yao, Y. Kanai; Efficient exact exchange using Wannier functions and other related developments in planewave-pseudopotential implementation of RT-TDDFT. J. Chem. Phys. 14 July 2024; 161 (2): 024111.