Accelerating Hybrid XC in RT-TDDFT using Maximally-localized Wannier functions

The use of accurate exchange-correlation (XC) functionals with the exact exchange greatly enhances our ability to model the electron dynamics in complicated systems using real-time time-dependent density functional theory (RT-TDDFT). However, the computational cost of hybrid XC can be extremely large particularly for condensed phase systems, being often more than two orders of magnitude larger than that of using standard GGA approximations. Such a large computational cost becomes prohibitive especially in RT-TDDFT simulation. Building on our recent work on propagating maximally-localized Wannier functions (MLWFs) in RT-TDDFT, we discuss our effort on significantly reducing the cost of the exact exchange evaluation for hybrid XC. For insulating systems, time-dependent MLWFs remain spatially localized, and the computational cost can be reduced by as much as one order of magnitude without compromising the accuracy. We will discuss a few examples for demonstrating this methodology using the plane-wave pseudopotential implementation of RT-TDDFT.