Joint Chemical and Biological Physics and Molecular Chemistry and Materials Science Guest Seminar

Date:
13
Tuesday
June
2023
Lecture / Seminar
Time: 10:00-11:00
Title: Tunneling and Zero-Point Energy Effects in Multidimensional Hydrogen Transfer Reactions
Location: Gerhard M.J. Schmidt Lecture Hall
Lecturer: Dr Yair Litman
Organizer: Department of Chemical and Biological Physics
Details: University of Cambridge
Abstract: ydrogen transfer reactions play a prominent role in nature and many technologica ... Read more ydrogen transfer reactions play a prominent role in nature and many technological applications. Despite appearing to be simple reactions, they constitute complex processes where nuclear quantum effects (NQE) such as zero-point energy and nuclear tunneling play a decisive role even at ambient temperature. In this talk, I will show how state-of-the-art methodologies based on the path integral formulation of quantum mechanics in combination with the density functional approximation provide the unique possibility to theoretically address these effects in complex environments. The first part of the talk will focus on the porphycene molecule in the gas phase and adsorbed on metallic surfaces. The porphycene molecule constitutes a paradigmatic example of a molecular switch and has recently received great attention due to its intriguing hydrogen dynamics. I will demonstrate how a correct treatment of NQE, as well as the inclusion of multidimensional anharmonic couplings, are essential to obtain qualitatively correct results regarding the non-trivial temperature dependence of the hydrogen transfer rates and vibrational spectra [1-3]. Finally, I shall also mention some of our recent results for hydrogen diffusion on metals for which non-adiabatic effects, in addition to NQE, play a significant role and can lead to “quantum localization” [4-6]. [1] Y. Litman, J. O. Richardson, T. Kumagai, and M. Rossi, J. Am. Chem. Soc. 141, 2526 (2019) [2] Y. Litman, J. Behler, and M. Rossi, Faraday Discuss. 221, 526 (2020) [3] Y. Litman and M. Rossi, Phys. Rev. Lett. 125, 216001 (2020) [4] Y. Litman, E. S. Pos. C. L. Box, R. Martinazzo, R. J. Maurer, and M. Rossi, J. Chem. Phys. 156, 194106 (2022) [5] Y. Litman, E. S. Pos. C. L. Box, R. Martinazzo, R. J. Maurer, and M. Rossi , J. Chem. Phys. 156, 194107 (2022) [6] O. Bridge, R. Martinazzo, S. C. Althorpe, Y. Litman, in preparation (2023)
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