Intramolecular energy transfer crossing

Zhao and Rice then developed an approximation to locate the intramolecular bottlenecks and calculate the associated flux. There are two principal motivations for the development of such an approximation. These are, first, the need to simplify the very complicated mapping-based calculation of the flux crossing a cantorus so as to make the calculation practical in systems with many DOFs and, second, the desirability of having a simple representation of the intramolecular energy transfer barrier in terms of molecular properties. 

The experimental data surveyed in Section III have several striking features. Although the data base is too small to permit definitive conclusions to be drawn, it seems likely that the extremely large cross-sections and the existence of propensity rules will be characteristic of all collision-induced intramolecular energy transfer in electronically excited molecules. 

Finally, we consider the performance of the MFT method for nonadiabatic dynamics induced by avoided crossings of the respective potential energy surfaces. We start with the discussion of the one-mode model. Model IVa, describing ultrafast intramolecular electron transfer. The comparison of the MFT method (dashed line) with the quantum-mechanical results (full line) shown in Fig. 5 demonstrates that the MFT method gives a rather good description of the short-time dynamics (up to 50 fs) for this model. For longer times, however, the dynamics is reproduced only qualitatively. Also shown is the time evolution of the diabatic electronic coherence which, too, is... 

Finally, we discuss applications of the ZPE-corrected mapping formalism to nonadiabatic dynamics induced by avoided crossings of potential energy surfaces. Figure 27 shows the diabatic and adiabatic electronic population for Model IVb, describing ultrafast intramolecular electron transfer. As for the models discussed above, it is seen that the MFT result (y = 0) underestimates the relaxation of the electronic population while the full mapping result (y = 1) predicts a too-small population at longer times. In contrast to the models... 

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