Regensburg 2022 – scientific programme

Parts | Days | Selection | Search | Updates | Downloads | Help

MM: Fachverband Metall- und Materialphysik

MM 12: Computational Materials Modelling: Physics of Ensembles 1

MM 12.9: Talk

Tuesday, September 6, 2022, 12:30–12:45, H44

Boosting first-principles molecular dynamics with orbital-free density functional theory — •Lenz Fiedler¹, Zhandos A. Moldabekov¹, Xuecheng Shao², Kaili Jiang², Tobias Dornheim¹, Michele Pavanello², and Attila Cangi¹ — ¹Helmholtz-Zentrum Dresden-Rossendorf / CASUS — ²Rutgers University Newark

Kohn-Sham density functional theory (KS-DFT) is one of the most important simulation methods in materials science and quantum chemistry. Yet, standard DFT codes exhibit scaling behaviors in terms of system size and temperature that prohibit extended dynamical investigations of materials using DFT driven molecular dynamics simulations (MD), especially towards the warm dense matter regime (WDM). We present a practical hybrid approach that combines orbital-free density functional theory (DFT) with Kohn-Sham DFT for speeding up first-principles molecular dynamics simulations. Equilibrated atomic configurations are generated using orbital-free DFT for subsequent Kohn-Sham DFT molecular dynamics. This leads to a massive reduction of the simulation time without any sacrifice in accuracy. We show results across systems of different sizes and temperature, up to the warm dense matter regime. To that end, we use the cosine distance between the time series of radial distribution functions representing the ionic configurations. Likewise, we show that the equilibrated ionic configurations from this hybrid approach significantly enhance the accuracy of machine-learning models that replace Kohn-Sham DFT.