Description du sujet de thèse

Electron attachment processes by a molecular system are ubiquitous and remain poorly understood. Examples of these include the Inter-particle Coulombic electron capture (ICEC) process in which a free electron is attached to a molecular system and the excess energy leads to the ionisation of a neighbouring system (atom, molecule) [1], atmospheric reactions such as the electron-mediated dissociation of molecular oxygen into reactive O atoms [2] or electron-induced astrochemical processes which initiate chains of reactions leading to the formation of relevant astrochemical species such as formaldehyde or methanol [3]. This lack of comprehension stems from major technical and methodological bottlenecks that hinder the efficient and accurate simulation of the electron dynamics. Moreover, a common hypothesis in most of the current studies is that nuclei remain fixed during the whole process.[4] However, it is known that nuclear dynamics do play an important role influencing the efficiency and chemical evolution of the system. This Ph.D. thesis, in direct collaboration with a multinational team (Germany, France and Argentina) will set up the necessary methodology for these studies and will perform accurate quantum dynamical simulations in realistic systems including nuclear motion. For this we will make use of the MCTDH quantum dynamical software package [5] together with our recent methods for the compact and accurate representation of operators [6] which will be essential to achieve efficient simulations.

[1] K. Gokhberg and L. S. Cederbaum Phys. Rev. A. 82, 052707, (2010).
[2] N. J. Mason, B. Nair, S. Jheeta, E. Szymanska, Faraday Discuss., , 168, 235 (2014).
[3] F. Schmidt, P. Swiderek, J. H. Bredehöft, ACS Earth Space Chem., 3, 1974−1986 (2019).
[4] A. Haller, D. Peláez, A. Bande, J. Phys. Chem. C 123, 14754−14765 (2019).
[5] H.-D. Meyer, F. Gatti, and G. A. Worth, Multidimensional Quantum Dynamics: MCTDH Theory and Applications Wiley-VCH (2009).
[6] R. L. Panadés-Barrueta, D. Peláez, J. Chem. Phys. 153, 234110 (2020) ; Q. Song, X. Zhang, D. Peláez, Q. Meng, J. Phys. Chem. Lett., 13, 11128−11135 (2022); N. Nadoveza, R. L. Panadés-Barrueta, L. Shi, F. Gatti, D. Peláez, J. Chem. Phys. (under review) ; N. Nadoveza, R. L. Panadés-Barrueta, L. Shi, F. Gatti, D. Peláez Eur. Phys. J. (under review).

Contexte de travail

The Institut des Sciences Moléculaires d'Orsay (ISMO - UMR 8214) is a research unit created in 2010, associated with the CNRS and the University of Paris-Sud, resulting from the merger of three laboratories in Orsay: the Laboratory of Molecular Photophysics [LPPM (UPR3361)], the Laboratory of Atomic and Molecular Collisions [LCAM (UMR8625)] and the Laboratory of Interaction of X-rays with matter [LIXAM (UMR8624)]. The ISMO aims to be a centre of excellence in its three main scientific fields: molecular physics and its applications, nanosciences, and physics for biology, which are based on a common foundation corresponding to two types of approaches: photophysics (a large part of the light spectrum, from X to infrared, is used to probe the dynamics induced by the optical excitation of the systems studied) and imaging: optical and local probe. The ISMO is at the interface of many fields: astrophysics, atmospheric chemistry, biology, medicine, etc.