Real-time time-dependent density functional theory for high-energy density physics

TL;DR

This paper reviews the application of real-time time-dependent density functional theory (TDDFT) to high-energy density systems, highlighting its ability to accurately predict dynamic electronic responses relevant to astrophysics and fusion research.

Contribution

It provides a comprehensive overview of real-time TDDFT formalism, practical computation methods, and future development directions for high-energy density physics applications.

Findings

Accurately predicts dynamic response properties of HED materials.

Captures both collective and non-collective electronic behaviors.

Applicable beyond linear-response regime.

Abstract

Electronic response properties of high-energy density (HED) systems influence planetary structure, drive evolution of fusion targets, and underpin diagnostics in laboratory astrophysics. Real-time time-dependent density functional theory (TDDFT) offers a versatile modeling framework capable of accurately predicting the dynamic response of HED materials -- including free-free, bound-free, and bound-bound contributions without requiring ad hoc state partitioning; capturing both collective and non-collective behavior; and applicable within the linear-response regime and beyond. We review the theoretical formalism of real-time TDDFT as applied to HED systems, provide a practical tutorial for computing relevant response properties (dynamic structure factors, conductivity, and stopping power), and comment on avenues for further development of this powerful computational method in service of HED science.