Comparison of two schemes for investigating NaCs photodissociation

The present work investigates the photoabsorption cross section of NaCs by using the split operator-Fourier transform propagation scheme and the Chebyshev polynomial expansion scheme. The comparison of the two calculated results shows that the split operator scheme can better exhibit the intermediate results of the dynamics process, while the other scheme is hard to satisfy this requirement due to the long time step. In this paper the photoabsorption cross sections, corresponding to the wave packet of the different vibrational state in the ground state transited to the excited state, also are calculated. The results show that the initial wave packet has a certain impact on photoabsorption cross section. The photoabsorption cross section corresponding to the related vibrational state shows a resonant behavior, i.e. the number of the minimum of the cross section corresponding to the each vibrational state is exactly equal to the number of the node of the wave function in the ground vibrational state. This situation caused by the reflection of the wave packet is accordance with the well-known reflection principle. (authors)