Research themes

Computational atomic structure

Calculation of atomic structures and data including energy levels, electronaffinities, radiative and non-radiative transition rates, lifetimes of excited levels, fine and hyperfine parameters, isotope shifts of neutral atoms, negative and multicharged ions. These atomic data are relevant in astrophysics, plasmas physics, thermonuclear fusion research programs and in the study of earth and planetary atmospheres. We contribute to the development of methods and computer codes for calculating electronic wave functions and spectroscopic properties, including correlation and relativistic effects.

Ab initio calculation of molecular structures

Quantum Chemistry methods are used to calculate the structure and the dynamics of small stable and unstable molecular species, having a direct experimental interest in fields like chemical reactivity, spectroscopy, atmospheric chemistry and astrophysics. We mainly focus on excited electronic and vibrational states, which play a decisive role in many reactive processes (dissociation, predissociation, isomerization, intramolecular vibrational relaxation...). Adapted methods of calculation are developed in order to take the underlying interactions into account (electron correlation, vibrational anharmonicity, vibronic coupling, intra-molecular interactions). We also perform ab initio calculations on the building blocks of biomolecules, marking a special interest for the ionisation phenomena relevant in the field of radiative damage to the genetic material.

Atomic and molecular dynamics and reactivity

In this research project we study the properties (energies, radiative transition probabilities, autoionization rates and population mechanisms) of multiply excited states formed during collisions of atoms with photons, ions, molecules, metallic surfaces and high-energy alpha particles. We are developing wave-packet propagation methods for calculating photodissociation and electron transfer cross-sections.