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Mardi 7 octobre 2008 — 14:00

A combined TDDFT-MD study of irradiated organic molecules

Zhiping WANG (LPT, Toulouse)

par Pierre Pujol - 7 octobre 2008

It is well known that the ionizing radiations upon biological material which can cause undesirable biological consequences evoke more and more scientific interest. The ionizing radiation has been studied extensively on macroscopic and mesocopic scale while the investigation of ion-induced fragmentation dynamics of single biomolecules is a relatively young field. Theoretically, time-dependent density functional theory (TD-DFT) has attracted much more attention to study the transient dynamics of electrons and ions during the ionizing radiations owing to its reasonable level of simplicity and accuracy. Using TD-DFT, applied to valence electrons, coupled non-adiabatically to molecular dynamics (MD) of the ions, we study different irradiation mechanisms of organic molecules, such as ethylene and water. For ethylene, we explore the laser excitation in the linear as well as in the non-linear domains by playing with the intensity and the frequency of the laser. And for water, we investigate collision processes with both charged and neutral projectiles. We systematically study the influence of the projectile velocity and of the impact parameter on the ionization of the water molecule.