Radiationless transitions promoting mode

The vibrational modes in radiationless transitions have been classified by Lin and Bersohn [30] into promoting modes like Q in Rha(f) and accepting modes, other vibrational modes participating in accepting the electronic energy fty)a [30-34]. In Eq. (64) for simplicity it is assumed that there is only one promoting mode involved in IC. Suppose... 

In Eq. 6, is the electronic matrix element involving the promoting mode p F j is the FC factor for mode j and p( nj ) is the density of states weighted FC factor for the set n, where Ft,- represents the most probable (i.e., optimal) distribution of the vibrational quanta in the final state. The function p( fij ) accounts for the contributions to the FC factor of modes other than). For the radiationless transition originating from the zero-point level of mode j, the FC factor is given by... 

In order to simplify the calculation of the average decay rate in Eq. 12, Sobolewski [19] divides the vibrational degrees of freedom into three categories promoting modes (p), accepting modes (a), and nonactive modes (n). The nonactive modes have vibrational wave functions that are orthogonal in the two electronic states (initial and final) and cannot promote the radiationless transition for symmetry reasons. Because the nonradiative decay rate depends on the vibrational quantum numbers of the accepting... 

As a further illustration of the general formalism developed in Chapter 3, we discuss the dependence of radiationless transition on temperature. One can distinguish clearly in Equations 3.75 and 3.77 between two contributions (of difference sources) to the temperature dependence. The dominant effect is given by the coth factor associated with the promoting modes. The second contribution is associated with the large number of accepting modes. At T = 0, all values in Equation 3.77 have to be... 

---