Published online by Cambridge University Press: 30 March 2016
The present report is a summary of a study, made in collaboration with P. Solomon, on the formation of interstellar molecules by radiative association and chemical reactions. The model to be discussed is limited practically to gas phase reactions in an HI region, where the principal constituents are atomic. It therefore is limited in scope and applicability. The role of the interstellar dust in this model is passive. It shields the region from radiation. Since a number of molecular species are dissociated by radiation and the extent of carbon ionization is determined by radiation, the radiation density is important in determining compositional equilibria.