Date:
Thu, 15/06/2023 - 11:00 to 12:00
Location:
Los Angeles Bld., Jerusalem, Israel
Abstract
Hydrogen 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].
Hydrogen 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].