Electron dynamics in extended systems within real-time time-dependent density-functional theory

Due to a beneficial balance of computational cost and accuracy, real-time time-dependent density-functional theory has emerged as a promising first-principles framework to describe electron real-time dynamics. Here we discuss recent implementations around this approach, in particular in the context of complex, extended systems. Results include an analysis of the computational cost associated with numerical propagation and when using absorbing boundary conditions. We extensively explore the shortcomings for describing electron-electron scattering in real time and compare to many-body perturbation theory. Modern improvements of the description of exchange and correlation are reviewed. In this work, we specifically focus on the Qb@ll code, which we have mainly used for these types of simulations over the last years, and we conclude by pointing to further progress needed going forward.

Automated summary

Real-time time-dependent density-functional theory is a promising first-principles framework for describing electron real-time dynamics. This paper discusses recent implementations of this approach, particularly in the context of complex, extended systems. The results include an analysis of the computational cost associated with numerical propagation and the use of absorbing boundary conditions, as well as a comparison to many-body perturbation theory.