Abstract

The interaction of the ionic ground state XO⁺ and the covalent excited state AO⁺ of diatomic Nal results in an avoided crossing and an upper adiabatic bound state with a photo-absorption spectrum extending from the ultraviolet to the visible. Nal is the only alkali halide vapour which shows line structure in this region of the spectrum, all others show a dissociation continuum. Previous attempts to analyse this line spectrum have been prevented because of the high temperature of the Nal vapour which results in a high density of rotational lines and the additional complication caused by the fragmented nature of the bands due to broadening by predissociation. The fluorescence excitation spectrum is much less dense and has allowed angular momentum assignments of the rotational band fragments in a limited region of the spectrum and a suggested potential curve based on this excitation data [1]. This potential, however, is not in agreement with potentials based on dissociation data [2] with the difference well outside the range of experimental error.

© 1996 Optical Society of America