Berlin 2012 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 17: Poster Session
MM 17.72: Poster
Montag, 26. März 2012, 17:00–19:00, Poster B
Ehrenfest molecular dynamics within the projector augmented-wave method — •Ari Ojanperä1, Ville Havu1, Lauri Lehtovaara2, Arkady Krasheninnikov1,3, and Martti Puska1 — 1Department of Applied Physics, Aalto University, Finland — 2LPMCN, Université Claude Bernard Lyon 1, France — 3Materials Physics Division, University of Helsinki, Finland
Modeling nonadiabatic processes, such as ion-atom collisions and electron transfer in molecular and biological systems, represents major computational challenges because multiple potential energy surfaces (PESs) are involved in the dynamics. Consequently, traditional ab initio molecular dynamics (AIMD) methods, founded on the assumption that the electronic subsystem is in its ground state, cannot be used. Ehrenfest molecular dynamics (Ehrenfest MD) within time-dependent density functional theory (TDDFT) offers a computationally affordable approach to simulating nonadiabatic processes by coupling the quantum equations of motion for electrons with classical equations of motion for nuclei via an average potential surface.
We have implemented Ehrenfest MD within the projector augmented wave (PAW) method. The electronic structure program used for the implementation is GPAW, which uses real space grids and finite differences. We demonstrate the applicability of our method by studying electronic stopping in graphene. We find that our PAW-based Ehrenfest MD results agree well with previous Troullier-Martins pseudopotential calculations. Moreover, the agreement with experiments is good as long as the effect of core electron excitations is small.