Abstract

The present work is focused on the photoionization of prototypical biomolecular chromophores such as furan, pyrrole and tiophene from the ground state and from the first lowest-lying excited states. The photochemical and photoionization properties of these molecules are of great interest due to an extensive collection of available experimental and theoretical results [1,2]. This work is part of a wider project which concerns a high level theoretical description of Timeresolved photoelectron spectroscopy (TRPES) observables obtained from pump-probe experiments. In particular, we combined photoionization observables calculation, using Dyson orbitals, with trajectory-based nonadiabatic dynamics calculation of prototype chromophores. The final goal is an accurate and computationally efficient simulation of TRPES experiments. The use of Dyson orbitals, recently implemented [3], allows the description of ionization from excited states at the single channel level, and a correlated description of the initial and final ionic bound states. The Dyson orbitals were computed at the TDDFT, ADC(2) and CASSCF levels. The high quality calculations of the photoionization dynamical observables are performed via an accurate solution of the continuum one particle wavefunctions in a multicenter B-spline basis, at the DFT and TDDFT levels, which provides an adequate description of the electronic continuum [4]. The approach can be conveniently used to provide results for a series of snapshots along the trajectories generated.

[1] T. Fuji et al., J. Chem. Phys., 133, 234303, 2010

[2] A. Humeniuk, M. Wohlgemuth, T. Suzuki and R. Mitrić, J. Chem. Phys, 139, 2013

[3] A. Ponzi, C. Angeli, R. Cimiraglia, S. Coriani and P. Decleva, J. Chem. Phys., 140, 2014

[4] M. Stener, G. Fronzoni and P. Decleva, J. Chem. Phys., 122, 2005

About the speaker

Aurora Ponzi received her Master Degree in Chemistry from the Sapienza University of Rome in 2010, and her Ph.D. degree in Theoretical Chemistry at the University of Trieste in 2015, under the supervision of Prof. Piero Decleva. Her PhD thesis focused on the study of the dynamics of photoemission processes for atoms and molecules. Since October 2015 she has been a post-doctoral researcher at the theoretical chemistry group of the Ruđer Bošković Institute in Zagreb. Her research project aims at a high level theoretical description of Time-Resolved Photoelectron Spectroscopy (TRPES) observables obtained from pump-probe experiments. TRPES permits to probe electronic states and nuclear dynamics with femtosecond time resolution. The goal of her research is the combination of photoionization observables calculation (using Dyson orbitals) with semiclassical nonadiabatic dynamics calculation. 

Recent publications

• Photoionization of furan from the ground and excited electronic states by A. Ponzi, M. Sapunar, C. Angeli, R. Cimiraglia, N. Doslic and P. Decleva, J. Chem. Phys. 144, 084307 (2016)
• Photoionization of endohedral atoms: Molecular and interchannel-coupling effects by A. Ponzi, P. Decleva and S. T. Manson, Phys. Rev. A 92, 023405 (2015)

Participation

The lecture is open to all and advance registration is not necessary.

Organiser and contact

Sonia Coriani, AIAS-COFUND Senior Fellow
Aarhus Institute for Advanced Studies (AIAS),
Aarhus University
soniac@aias.au.dk

Phone: +45 87153691
Room 111, Build. 1630