The main aim of this thesis is the development and description of a quantum mechanical wavepacket model of intramolecular vibrational energy redistribution (IVR) in molecules. Over the course of the thesis, it is shown how this model may be derived from an initial quantum mechanical description of large amplitude
vibrational modes.
In Chapters 2 and 3, a pedagogical account is given of the methods of constructing, propagating and analysing a wavepacket description of a large amplitude vibrational mode.
In Chapter 4, further analytical techniques are developed for the study of a dynamical wavepacket. A method of Quantum Trajectory analysis is developed, which unlike the existing Quantum Trajectory Method is applicable to the study of wavepackets which exhibit Quantum Tunnelling. Novel applications of a Quantum Phase Space analysis of a wavepacket are also presented. These allow a simultaneous analysis of the momentum and positional behaviour of a wavepacket propagated in both single and double minimum potential functions.
The observation of phase-shifted quantum beats m fluorescence decay spectra has led to the identification IVR m electronically excited molecules.
Applying the wavepacket techniques developed in Chapters 2-4, a quantum mechanical model description of this dynamic energy transfer process between normal vibrational modes is constructed.
This model is shown to reproduce successfully the limited energy transfer dynamics obtained from experimental results, and to improve upon this picture by providing additional insight into the intricate nature of energy transfer between normal modes of vibration in an electronically excited molecule.