New Rydberg–Rydberg Transitions of the ArH and ArD Molecules: III. Emission from the 4fComplexes

✍ Scribed by I. Dabrowski; D.W. Tokaryk; R.H. Lipson; J.K.G. Watson

• Publisher: Elsevier Science
• Year: 1998
• Tongue: English
• Weight: 610 KB
• Volume: 189
• Category: Article
• ISSN: 0022-2852
• DOI: 10.1006/jmsp.1997.7524

✦ Synopsis

We report observations and analyses of bands in the spectra of the ArH and ArD molecules due to emission from the 4 f Rydberg complexes. For ArD, the observed bands are 4 f r 5s and 4 f r 3dl for all three components l Å 0, 1, and 2 of the 3d state. These give direct information on all 14 spin-orbit components of the 4 f complex. For ArH, the data is more limited because the levels of the 5s state are broadened by predissociation, and only the l Å 2 component of the 4 f r 3dl transitions is seen clearly, although a number of lines could be assigned to the 4 f r 3dp band, which is strongly overlapped by the 6s r 4p band. The 4 f complexes of both isotopes are good example of Hund's case (d) coupling. The 4 f orbitals are essentially non-core-penetrating, so that spin-orbit coupling is negligible for them, and the zero-rotation splitting agrees well with calculations from the ab initio quadrupole moment and anisotropic polarizability of the core. The orbit-rotation coupling parameter j 4f gives a value of the core electric dipole moment that is in reasonable agreement with ab initio and previous experimental values. A summary of the presently known states of ArH and ArD is presented.