Ultrafast dynamics of IVR in molecules and reactions

This chapter builds on an earlier contribution [1] which was devoted to the description of intramolecular vibrational-energy redistribution (IVR) and its manifestations in time-domain experiments. IVR is the process by which energy that is initially localized in a particular vibrational motion of a species redistributes in time such that different vibrational motions of that species gain energy at the expense of the initial motion. The process is at the heart of vibrational state specificity in intramolecular dynamics. If IVR spreads energy over a larger number of vibrations in a time short compared with other intramolecular decay processes, then memory of the initial state is lost for those other processes and with it the possibility of state-specificity. Thus, insofar as vibrational character influences molecular dynamics, the characterization of IVR is essential to the understanding of this dynamics