Direct Non-adiabatic Simulations of the Photoinduced Charge Transfer Dynamics

Abstract

We apply direct non-adiabatic dynamics simulations to investigate photoinduced charge transfer reactions. Our approach is based on the mixed quantum-classical fewest switches surface hopping (FSSH) method that treats the transferring electron through time-dependent density functional theory and the nuclei classically. The photoinduced excited state is modeled as a transferring single-electron that initially occupies the LUMO of the donor molecule/moiety. This single-particle electronic wavefunction is then propagated quantum mechanically by solving the time-dependent Schr\"odinger equation in the basis of the instantaneous molecular orbitals (MOs) of the entire system. The non-adiabatic transitions among electronic states are modeled using the FSSH approach within the classical-path approximation. We apply this approach to simulate the photoinduced charge transfer dynamics in a few well-characterized molecular systems. Our results are in excellent agreement with both the experimental measurements and high-level (yet expensive) theoretical results.