Atmospheric photochemical loss of H and H2 from formaldehyde: the relevance of ultrafast processes
Abstract
We have performed ab initio calculations to examine the potential energy along the normal modes of ground-state HCHO and along the reaction coordinates for loss of H2 and atomic hydrogen, respectively. This exploration showed that there are no specific features that will lead to reaction on the excited-state surfaces for excitations that are relevant to the troposphere and stratosphere. The calculations did however lead to the localization of a conical intersection point through which a specific loss of H2 could take place. However, the conical intersection lies at 5.4 eV relative to the ground state molecule at equilibrium and is thus inaccessible via single