dr. Ivano Tavernelli: Nonadiabatic dynamics of complex molecular systems: a synergy between theory and experiments

ABSTRACT

In the mixed quantum-classical description of molecular systems, only the quantum character of the electronic degrees of freedom is considered while the nuclear motion is treated at a classical level. In the adiabatic case, this picture corresponds to the Born-Oppenheimer limit where the nuclei move as point charges on the potential energy surface (PES) associated with a given electronic state. Despite the success of this approximation, many physical and chemical processes do not fall into the regime where nuclei and electrons can be considered decoupled. In particular, most photoreactions pass through regions of the PES in which electron-nuclear quantum interference effects are sizeable and often crucial for acorrect description of the dynamics. Several strategies are nowadays available to solve (at least approximately) the quantum dynamics of the nuclei: the wavepacket dynamics in a space of reduced dimensionality (e.g. using Multi Configuration Time Dependent Hartree, MCTDH), the multiple-spawning technique, and the trajectory-based approaches.