What determines the disposal of energy in the products of electronically inelastic collisions? A comparative case study of SiCl and SiF

Abstract

Although the rates of collisional removal of electronically excited states of small molecules have been extensively characterised, a general understanding of the factors which determine the branching over available product levels is still lacking. The purpose of this article is to shed light on this field by concentrating on the information which has been collected on one particular family of systems, excited states of the silicon halides SiCl and SiF. An extended interpretation of the data in terms of the relevant potential energy surfaces is presented. The specific conclusions are set in the context of other related work. How they reflect on the likely viability of simple empirical models is discussed. Opinions are offered on future experimental directions which are likely to be fruitful, and a pressing general need for complementary theoretical support is identified.