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arXiv · 1907.06721

Modeling solid-liquid interface reactions with next generation extended Lagrangian quantum-based molecular dynamics

Kevin G. Kleiner·Aparna Nair-Kanneganti·Christian F. A. Negre·Ivana Matanovic·Anders M. N. Niklasson
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Abstract

We demonstrate the applicability of extended Lagrangian Born-Oppenheimer quantum-based molecular dynamics (XL-BOMD) to model electron transfer reactions occurring on solid-liquid interfaces. Specifically, we consider the reduction of O$_2$ as catalyzed at the interface of an N-doped graphene sheet and H$_2$O at fuel cell cathodes. This system is a good testbed for next-generation computational chemistry methods since the electrochemical functionalities strongly depend on atomic-scale quantum mechanics. As opposed to prior iterations of first principles molecular dynamics, XL-BOMD only requires a full self-consistent-charge relaxation during the initial time step. The electronic ground state and total energy are stabilized thereafter through nuclear and electronic equations of motion assisted by an inner-product kernel updated with low-rank approximations. A species charge analysis reveals that the kernel-based XL-BOMD simulation can capture an electron transfer between the PGM-free catalyst and a solvated O$_2$ molecule mediated by H$_2$O, which results in the molecular dissociation of O$_2$.

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Kevin G. Kleiner, Aparna Nair-Kanneganti, Christian F. A. Negre, Ivana Matanovic, Anders M. N. Niklasson. 2020-06-27. Modeling solid-liquid interface reactions with next generation extended Lagrangian quantum-based molecular dynamics. https://arxiv.org/abs/1907.06721

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