New Rydberg–Rydberg transitions of the ArH and ArD molecules. I. Emission from np states of ArD
| Autor: | J. K. G. Watson, I. Dabrowski, Michel Vervloet, D. W. Tokaryk |
|---|---|
| Rok vydání: | 1996 |
| Předmět: | |
| Zdroj: | The Journal of Chemical Physics. 104:8245-8257 |
| ISSN: | 1089-7690 0021-9606 |
| DOI: | 10.1063/1.471578 |
| Popis: | The ground electronic state of argon hydride has a repulsive potential apart from a long‐range van der Waals minimum, but the Rydbergexcited states have bound potentials similar to those of the ion ArH+. These states can be described approximately in terms of united‐atom quantum numbers nl. We report here rotational analyses of the bands 5p→5s, 5p→6s, and 6p→5s of ArD, which help to further characterize the npRydberg series. In ArH the bands 5p→5s and 6p→5s have broad lines because of predissociation in the lower state, and 5p→6s is difficult to analyze without further information. The present data are fitted with a Hund’s case (d) effective Hamiltonian. In previous work the 4p state was found to have a very small σ‐π splitting, but this does not hold for the higher np states, and is probably due to an accidental cancellation between electrostatic and polarizability contributions. On the other hand, the spin–orbit coupling decreases monotonically with n. Features of the rotational levels are discussed in terms of the high‐J limiting quantum numbers l J =N−R and s J =J−N, where R≡N +, in particular the effect of spin–orbit coupling on the levels with (l J ,s J )=(−1,1/2) and (0,−1/2), which produces a tendency to Hund’s case e behavior in 4p, and a sharp avoided crossing in 6p. The corresponding avoided crossing in 5p would occur beyond the present range of observed J values. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|