Fluorescence excitation spectrum of the Si–Ar van der Waals complex

Abstract
We report here the fluorescence excitations spectrum of the Si–Ar van der Waals complex in the region of the (3p4s)3P–(3p2)3P atomic transition. Long progressions are observed, which have been assigned to a Π–Σ transition. The potential curves derived from the analysis of these progressions are discussed in terms of effects of spin–orbit coupling on van der Waals interactions.