ABSTRACT
This chapter introduces the time-dependent wave packet approach and the Fourier grid method. It reviews the strategy to obtain the resonance positions and widths based on the time-dependent wave packet approach. There has been considerable interest in the direct measurement of the transition state region of chemical reactions. New experimental approaches to transition state spectroscopy have been developed by several groups. Photodissociation experiments offer good opportunities for directly probing the transition state of electronically excited states. Quantum dynamics at the transition state region can be formulated in time-independent as well as time-dependent terms. Rigorous time-independent quantum mechanical treatments such as the close-coupling approach are, however, limited to relatively simple systems. There has been considerable interest in the direct measurement of the transition state region of chemical reactions. New experimental approaches to transition state spectroscopy have been developed by several groups.
