I. Dabrowski et al., NEW RYDBERG-RYDBERG TRANSITIONS OF THE ARH AND ARD MOLECULES - II - EMISSION FROM ND AND NS STATES TO THE 4P STATE, Journal of molecular spectroscopy, 189(1), 1998, pp. 95-109
Citations number
40
Categorie Soggetti
Spectroscopy,"Physics, Atomic, Molecular & Chemical
We report and rotationally analyze new spectra of the ArH and ArD mole
cules corresponding to the 0-0 vibrational bands of electronic transit
ions from the nd and ns states to the 4p Rydberg complex, in united at
om notation. In ArD, our observation of the 3d delta state, along with
previous observations of the 3d pi and 3d sigma states, demonstrates
that the components of the 3d state are widely separated and can be tr
eated as Hund's case (b) states, unlike the components of the np and 4
f states, which form closely coupled case (d) Rydberg complexes. The b
and 4d sigma --> 4p has also been assigned. The 4d pi component is kno
wn from previous work of Lipson, but as yet the 4d delta component is
unknown. Emission from the 6s and 8s states is also analyzed. From the
intensities in the rotational structure, there is evidence that the 6
s state interacts with the 3d sigma state. In ArH, we analyze the 0-0
bands of the 3d pi --> 4p, 3d delta --> 4p, 4d sigma --> 4p, and 6s --
> 4p transitions. Unlike the rotational levels of the 5s state, which
are heavily broadened by predissociation, the 4p levels of ArH are sha
rp, so we can perform a more accurate and detailed analysis for this i
sotope than was possible previously. Qualitative features of the ArH s
pectra essentially mirror those of ArD, except that emission from the
3d sigma state was not identified, possibly due to a perturbation part
icular to this isotope. (C) 1998 Academic Press.