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MO: Fachverband Molekülphysik

MO 6: Theory of Molecular Dynamics

MO 6.6: Talk

Tuesday, March 7, 2017, 12:30–12:45, N 25

Coupled electron-nuclear dynamics: A comparison of methods and dimensionality — •Thomas Schnappinger, Julius Zauleck, Robert Siemering, and Regina de Vivie-Riedle — Department Chemie, LMU München

The purpose of this work is a first comparison of two methods describing a coupled electron-nuclear dynamics: the purely quantum mechanical ansatz NEMol and the TD-DFT based Ehrenfest dynamics. For this purpose the dynamics of (Z)-3-aminoacrolein in the electronic ground state was analyzed. Using different quantum chemical methods the potential profile of tautomerism was calculated and the critical points of the reaction were identified to set up one-dimensional potential energy surfaces along the reaction.

We introduce a novel form of the NEMol ansatz which is formulated for a single electronic state. Using the one-dimensional potential energy surfaces of the tautomerism we are able to calculate the coupled electron-nuclear dynamic.

The comparison between the NEMol ansatz and the TD-DFT Ehrenfest dynamics is so far limited due to the difference in dimensionality. Therefore an approach for one-dimensional TD-DFT Ehrenfest dynamics is presented. In addition a short outlook is provided how to select and evaluate the chosen dimensions for a dynamic simulation.