PhD position in theoretical molecular physics, University of Rennes, France
In molecular physical chemistry, experimental and observational data can be obtained with such high precision that more subtil effects become visible and discriminating. One example is the coupling between electron and nuclei motions, often neglected in many models, which now needs to be taken into account. For theory to remain a reliable predictive tool with a precision similar to that of experiment, it is crucial to go beyond the Born-Oppenheimer approximation by explicitly including the non-adiabatic couplings between multiple electronic surfaces. In the case of small molecules exhibiting Jahn-Teller effects, a major advance has been achieved recently through the use of diabatic models based on artificial neural networks. This approach has proven to be particularly accurate and efficient for the interpretation of the photodetachment spectra of NO−3. The challenge for a more detailed understanding of molecular systems with non-adiabatic couplings is now to include the overall rotation in the theoretical description.
The proposed research program contains both a numerical development aspect based on in-house computer codes, together with applications to various systems of interest. The main part of the work will be to implement diabatic models with an appropriate analytical form for further studies such as time-dependent dynamics
(wave-packet propagation) or time-independent close-coupling approaches for scattering. Applications will include extending the study the NO3radical, the ro-vibrational spectroscopy of which will also be the object of experimental work in the department. A second application will concern spectral line profiles modified by collisions in systems such as HCl+He and Br+O.
Deadline for application: 14 April 2023