Rydberg states molecular hydrogen

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. 

In writing this equation, we have made use of Van Vleck s pure precession hypothesis [12], in which the molecular orbital /.) is approximated by an atomic orbital with well-defined values for the quantum numbers n, l and /.. Such an orbital implies a spherically symmetric potential and its use is most appropriate when the electronic distribution is nearly spherical. Examples of this situation occur quite often in the description of Rydberg states. It is also appropriate for hydrides like OH where the molecule is essentially an oxygen atom with a small pimple, the hydrogen atom, on its side. Accepting the pure precession hypothesis allows the matrix elements of the orbital operators to be evaluated since... 

The investigation into molecular hydrogen Rydberg states has gained... 

Many of the above comments on the spectrum of the hydrogen atom also apply to all atoms and molecules. To any given, precisely specified quantum state of an atomic or molecular ion which can be produced by direct photoionization, there corresponds one or more optically allowed Rydberg series. The energy levels of the series are given by an equation similar to Eq. (5), namely... 

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