A model for the quantum dynamics of Rydberg states of large molecules

A model for the dynamics of high Rydberg states in isolated large molecules is proposed. The model accounts for the interaction between the electron and the vibrational degrees of freedom of the core. These are modelled by an Ohmic bath in thermal equilibrium. A reduced-density-matrix description is introduced by tracing over the bath and eliminating the continuous part of the electronic spectrum. Predissociation channels are included in a phenomenological manner. The resulting Markovian master equation for the reduced density operator is solved numerically. The numerical solutions yield insight into the dynamics of thermally activated population redistribution and autoionization processes of high Rydberg states.