Franck-Condon process

The separability used here leads to a clear relationship between chemical species and ground state electronic wave functions. Each isomeric species is determined by its own stationary ground state electronic wave function. The latter determines a stationary arrangement of Coulomb sources which is different for the different isomers. The nuclei are then hold around a stationary configuration if eq.(10) has bound solutions. An interconversion between them would require a Franck-Condon process, as it is discussed in Section 4. 

The impulse model is applied to the interpretation of experimental results of the rotational and translational energy distributions and is effective for obtaining the properties of the intermediate excited state [28, 68, 69], where the impulse model has widely been used in the desorption process [63-65]. The one-dimensional MGR model shown in Fig. 1 is assumed for discussion, but this assumption does not lose the essence of the phenomena. The adsorbate-substrate system is excited electronically by laser irradiation via the Franck-Condon process. The energy Ek shown in Fig. 1 is the excess energy surpassing the dissociation barrier after breaking the metal-adsorbate bond and delivered to the translational, rotational and vibrational energies of the desorbed free molecule. 

A relatively constant Tafel slope for reactions not involving adsorption, and those involving adsorption with complete charge transfer across the double layer, distorted by second order effects, may also be explained in terms of a non-Franck-Condon process. Since adsorbed intermediates in charge transfer processes also show adsorption energies depending on potential in the same way as the potential energy barrier maxima, these should also follow the same phenomena. 

According to Fig. 27, the electron jump transition will only be half completed (50 % ionic) when the internuclear distance has decreased by 2 A from R0 to Rc. This rather overstates the case, since the ionic contribution, increasing as R decreases, will expand the Br2 internuclear distance. Thus, the Br2 electron affinity and hence Rc both increase. Moreover, the distance between R0 and Rc will be smaller for nonlinear configurations. Even so, the calculations show that the nuclei will move a distance 1 A during the electron jump transition, which is therefore a Franck-Condon process only in the sense that the vertical electron affinity governs the orbiting impact parameter. 

A different type of process has been studied by Ohmine,i the photoisomerization of ethylene in either Ar or water solvents. The ethylene begins on the planar ground state and is excited through a Franck—Condon process to the triplet excited state. This excited state has a minimum energy configuration that is twisted rather than planar. The excess energy present in the system in the initial configuration on the excited state surface (what Ohmine calls the... 

Moreover, the second-order nonlinear susceptibility (Pz) of DPN derivatives is higher than the value of related DPM derivatives, due to the n-n interaction in the gable conformation. Both transannular electronic transitions and hyperpoiarizability are Franck-Condon processes, which are favored in DPN, because the probability of a photon impacting the gable conformation in a free rotor is negligible. 

Ionic precursors of the sought neutrals should be structurally characterized. Ions in the gas phase may exist in various isomeric forms, so it is important to make sure that (i) the right isomer is formed, and (ii) that the ions of interest are isomerically pure. Neutralization is considered as a vertical Franck-Condon process and it is expected that the neutrals will retain the structure of the ion that has been neutralized. 

The observation or nonobservation of a recovery signal depends on several factors. First, collisional neutralization of ions may produce neutrals in their dissociative state(s). Electron transfer between the ion and the target is considered as a vertical Franck-Condon process. If the geometry of the ion is close to that of the neutral, the latter has a good chance of being formed as a stable species. When the geometry of the ion and the neutral are significantly different then the neutral is likely to be unstable. 

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