Rydberg spectra, excitation schemes

Figure 12. Level scheme of the rotationally resolved high-n Rydberg experiment. A first narrow-band laser pulse excites the molecule from the electronic ground state So into a single rotational state in the electronically excited S state. The frequency of the second laser pulse is scanned to obtain the rotationally resolved Rydberg spectrum shown in Fig. 13.

Figure 3. Photoionization threshold spectra for neodymium. The excitation scheme used in each case is shown on the figure. The scanned laser wavelength calibration is shown at the top of each spectrum. In (a) the 20 300.8 cm 1 level is populated and in (b) the 21 572.6 cm 1 level is populated. The threshold wavelengths indicated yield the same ionization limit value of 5.523 eV. The arrows labeled R. L. indicate the position of the Rydberg convergence limit (3).

Figure 6. Rydberg series in neptunium obtained by field ionization (double arrow) of laser-excited levels. The excitation scheme is shown on the figure. The spectrum contains two series, one converging to the 5f+6d7s7L5 ground state and the other convering to the % level at 24.27 cm 1 in the ion. For the series converging to the 5li level, the Rydberg level positions with n less than 40.7 (short markers) are calculated using a constant fractional defect of 0.3 (4).

Benzene has a relatively low ionization potential (9.247 eV or 74580 cm ) so that all transitions from a2u and many from eig will lie beyond it and lead to super-excited states The second 1P ivas shown to belong to the highest filled o orbital It is not our intention to treat the spectrum of benzene in detail we merely used it as an example for the benefit of the non-initiated Reader as a simple MO + Rydberg scheme without energies, vibronic interactions, a electrons, and so on. Since the... 

Iodine has been studied extensively by ZEKE spectroscopy, including 2-1-1 and 1-1-2 schemes carried out by Cockett and co-workers. In the first case, a number of centrosymmetric Rydberg excited states acted as resonant intermediate states, and in the second case, the valence B IIq state was the intermediate. These studies demonstrate how well ZEKE spectroscopy can give a detailed vibrationally resolved spectrum and how autoionization is unavoidable in the photoelectron spectroscopy of small molecules. 

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