MAKHLOUF Sandy: Modeling and simulation of the electronic structure of small environmental molecules. An example: Lanthanide halides and monoxides (Ce & Lu).

Thesis summary: Recent advances in the field of detection have highlighted the presence of atomic and / or molecular compounds in the interstellar medium previously unknown such as Lutetium and some of its molecular compounds (LuO, LuBr, LuF ...). Although these molecules are regularly the subject of experimental studies in catalysis such as LuBr and LuF, there is very little theoretical or experimental data on their spectroscopy. The experiments carried out mainly in the 1970s allowed the characterization of the ground state and the first excited state, revealing highly disturbed spectra that are difficult to interpret. Theoretically, only the ground state and the first two molecular states have been described to date by DFT calculations and there is no result on very excited states.

The study of the electronic structure of these molecules is difficult given the presence of an open layer and is a challenge that requires the application of specific calculation methods (DFT, CAS-SCF, ligand field ...) . Recently, we began to describe the electronic structure of Lutetium halides in a large energy domain (0-42000cm-1) using a CAS-SCF / MRCI approach including Davidson correction and coupling consideration. spin-orbit. The calculations performed on the Lutetium halides (LuI, LuBr, LuF and LuCl) compared to the experimental data, proved to be very precise and made it possible to highlight characteristic tendencies of these molecules, such as the nature of the ground state. order of the molecular states, the shape of the potential energy curves, the equilibrium position, the most important permanent and transition dipole moments as a function of the electroaffinity of the halide.

The proposed work is now to extend this study to lutetium oxide for which there are recent experimental results and then to molecules that are assimilated to environmental pollutants such as cerium oxide and its halides. The goal is to identify trends within these compounds to help understand the mechanisms of formation and evolution of these molecules. Due to the presence of 4f electrons on the valence layer, the ground state of these molecules is a 2Φ state which leads us to consider from the start the spin-orbit interaction to characterize it very precisely. Calculations will be made with the MOLPRO software. The student will thus be in charge of determining the parameters necessary for the calculations (basis, choice and nature of the potentials for each atom, construction of the configuration interaction space). He (she) will carry out all the calculations necessary for the characterization of the molecular states obtained. A simulation of the corresponding molecular spectra will complete this study.

MAKHLOUF Sandy - sandy.makhlouf.etu[chez]univ-lille[point]fr - FR: 07 66 30 64 22 - LB: +961 71 615586

PhD supervisor in France: MAGNIER Sylvie
Thesis supervisor in Lebanon: TAHER Fadia
Co-supervisor in Lebanon: ADEM Ziad