Absorption Spectrum of the NO Molecule. X. The 3d Rydberg Complex, its Vibrational Structure, Spin–Orbit Coupling, and Interactions with Non-Rydberg States

Abstract

The vibrational levels of the 3dσ,π Rydberg complexes of the NO molecule are studied. They give rise to absorption bands 3d–X in the vacuum ultraviolet, most of which are severely overlapped by other bands, and, in addition, to Rydberg–Rydberg emission bands in the visible (3d–3s) and in the infrared (3d–3p). Both types of spectra have been photographed at high resolution, the absorption spectra for three different isotopes.Interactions with non-Rydberg levels and predissociations are observed. A detailed analysis, including spin–orbit effects, is given of the crossing between the 3dσ,π(ν = 1) and B2Π(ν = 23) rotational levels. Off-diagonal matrix elements are determined and precise vibrational and rotational constants are calculated. Largely responsible for the unusual structure of the bands is the matrix element [Formula: see text] which is shown to be independent of ν.