Regensburg 2022 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 58: Poster Wednesday: New Methods and Developments, Frontiers of Electronic Structure Theory

O 58.3: Poster

Mittwoch, 7. September 2022, 18:00–20:00, P4

Enhanced Sampling of Surface Reactions Using Boltzmann Generators — •David Hering, Johannes T. Margraf, and Karsten Reuter — FHI Theory Department, Berlin, DE

Computational surface science and catalysis research is still mainly conducted with static density functional theory (DFT) calculations. This approach is computationally convenient, but misses important aspects of surface chemistry, such as anharmonic free energy contributions. In principle, DFT-based molecular dynamics (MD) simulations (ideally combined with enhanced sampling algorithms) would allow a much more accurate description of these processes. Unfortunately, these are far too expensive to be routinely applied to complex surface/adsorbate systems. This is due to the fact that configurations in MD are generated sequentially. As a consequence, MD configurations are not statistically independent so that a very large number of samples is required to obtain converged ensemble properties. To overcome this limitation, Noé and co-workers recently proposed a generative machine learning model called the Boltzmann Generator, which was used to generate independent configurations of biomolecules. In this contribution, we explore how Boltzmann Generators can also be used to sample the free energy surface of surface/adsorbate systems relevant for heterogeneous catalysis. In particular, training protocols and validation metrics of generated ensembles will be discussed.