Simulation of 24,000 Electrons Dynamics: Real-Time Time-Dependent Density Functional Theory (TDDFT) with the Real-Space Multigrids (RMG)
ORAL
Abstract
We present the theory, implementation, and benchmarking of a real-time time-dependent density functional theory (RT-TDDFT) module within the RMG code, designed to simulate the electronic response of molecular systems to external perturbations. Our method offers insights into non-equilibrium dynamics and excited states across a diverse range of systems, from small organic molecules to large metallic nanoparticles. Benchmarking results demonstrate excellent agreement with established TDDFT implementations and showcase the superior stability of our time-integration algorithm, enabling long-term simulations with minimal energy drift. The scalability and efficiency of RMG on massively parallel architectures allow for simulations of complex systems, such as plasmonic nanoparticles with thousands of atoms. Future extensions, including nuclear and spin dynamics, will broaden the applicability of this RT-TDDFT implementation, providing a powerful toolset for studies of photoactive materials, nanoscale devices, and other systems where real-time electronic dynamics is essential.
*This research was conducted at the Center for Nanophase Materials Sciences (CNMS), which is a US Department of Energy, Office of Science User Facility at Oak Ridge National Laboratory. This research used resources of the Oak Ridge Leadership Computing Facility at the Oak Ridge National Laboratory, which is supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC05-00OR22725. The development of RMG for exascale computers was supported by DOE's Exascale Computing Project (ECP), Project Number: 17-SC-20-SC, for DFT input to QMCPACK. Computing resources were provided through the Innovative and Novel Computational Impact on Theory and Experiment (INCITE) program and computational resources of the ACCESS (Advanced Cyberinfrastructure Coordination Ecosystem: Services & Support) program through allocation TG-DMR110037.
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Publication:[1] Jacek Jakowski, Wenchang Lu, Emil Briggs, David Lingerfelt, Bobby G. Sumpter, Panchapakesan Ganesh, Jerzy Bernholc, "Simulation of 24,000 Electrons Dynamics: Real-Time Time-Dependent Density Functional Theory (TDDFT) with the Real-Space Multigrids (RMG): (2024) [https://arxiv.org/abs/2410.09189]
