Rydberg states time scales

SEPARATION OF TIME SCALES IN THE DYNAMICS OF HIGH MOLECULAR RYDBERG STATES... 

There are many motivations for the study of the unusual dynamics of high Rydberg states of molecules. The two that most capture my imagination are the exceptionally wide range of time scales involved (Fig. 1) and the unusual limiting situation of a very slow electron being perturbed by the faster motion of the nuclei in the core about which it revolves. What this means is that, as one varies the hydiogenic principal quantum number n, it is possible... 

R. D. Levine The latest results for benzene as reported by Prof. Neusser suggest that benzene is the molecule we should study at all time scales. In other aromatic molecules (and also in other molecules [U. Even et al., J. Phys. Chem. 98, 3472 (1994)]) you have reported that there are at least two times scales for the decay of high Rydberg states. A faster (hundreds-of-nanosecond) scale and a slower one (microsecond range). Even the faster time scale is two to three orders of magnitude slower decay than one would expect from an extrapolation of the decay measured at low or intermediate n Rydberg states. 

The classical trajectory simulations of Rydberg molecular states carried out by Levine ( Separation of Time Scales in the Dynamics of High Molecular Rydberg States, this volume) remind me of the related question asked yesterday by Prof. Woste (see Berry et a]., Size-Dependent Ultrafast Relaxation Phenomena in Metal Clusters, this volume). Here I wish to add that similar classical trajectory studies of ionic model clusters of the type A B have been carried out by... 

The fragment excited-state NO(A2S+) is a molecular 3r Rydberg state, and we shall refer to this as NO(A, 3s). The observed NO(A, 3.v) product state distributions supported the notion of a planar dissociation involving restricted intramolecular vibrational energy redistribution (IVR) [176]. A scheme for studying NO dimer photodissociation dynamics via TRPES is depicted in Fig. 25. The NO(A, 3.v) + NO(X) product elimination channel, its scalar and vector properties, and its evolution on the femtosecond time scale have been discussed in a number of recent publications (see Ref. [175] and references cited therein). 

Frolov, A.M., Smith, V.H. Scaled-time dynamics of ionization of Rydberg Stark states by half-cycle pulses, J. Phys. B 1995,28, L449-56. 

---