Rydberg states crossings

In the cases treated in the present paper, we do not have a reorganization energy because, for example as shown in Figures 5 and 10, the two diabatic states between which electron transfer occurs (e.g., the SS a and excited-Rydberg states) cross so close (i.e., within the zero-point vibrational motion of the SS bond) to the minimum on the Rydberg-state surface as to render A essentially zero. In more traditional electron-transfer events, A contains contributions from the... 

Since the experimental work on H3 recombination provided much of the impetus for this work, we will compare two recent experiments, a merged-beam and a plasma afterglow experiment. We conclude that the results can be reconciled by postulating the formation of long-lived Rydberg states and that these are quite sensitive to the environment in which the recombination occurs. In beam experiments (Section TV. B ) the observed cross sections are shown to be sensitive to the presence of electric fields. In the afterglow experiments, the concentration of third... 

Since the formation of high Rydberg states is not a major mechanism in Hj recombination, the presence of electric fields has litde or no effect on the total cross section. This is also the case with the ion-pair reaction since this proceeds via a... 

If we suppose that these Rydberg states have non-negligible lifetimes against autoionization, as could occur via dispersion of the potential energy of the molecule into various vibrational modes, then these states would be very sensitive to electric fields in the measuring apparatus. It is suggested here that this is the reason for the large discrepancies between cross sections measured in the various beam experiments. 

Furthermore, we expect that intersystem crossing plays a minor role in the nonradiative relaxation of high Rydberg states in benzene. 

The main result of these first detailed experimental studies of the AI mechanism is that, even at thermal velocity, the system R -H follows a potential curve F ( R) that diabatically crosses an infinite number of potential curves dissociating into R+H, H being hydrogen in a Rydberg state, and continues to be well defined in the ionization continuum. We might mention that results on AI are also interesting because AI is the reverse reaction to the important process of dissociative recombination of molecular ions. 

Using these assumptions they could then fit their data to determine excitation cross sections, o(n, Wo), for the excitation of a Rydberg state of principal quantum number n by an electron of energy W0. They found the values of o (W0) given in... 

Table 3.1. Electron impact cross sections for the excitation of rare gas Rydberg states for the electron energy at the peak of the cross section and 100 eV.a...

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