Location of Two Seams in the Proximity of the C_(2v)pi pi* Minimum Energy Path of Formaldehyde

摘要

Photochemical reactions rationalization is a key aspect for the understanding and setup of novel experiment and novel photoinitiated pathways.In this respect,the relationship between minimum energy paths over an excited-state and the intersection to lower potential energy surfaces is fundamental.In order to help the understanding of this relationship,in this study we present a novel kind of constraint for geometry optimizations,namely,an"orthogonality"constraint.Its possible applications are described.A complete example on how to retrieve the direct relationship between a minimum energy path over an excited-state potential energy surface and a conical intersection seam is given for C_(2v)symmetry constrained formaldehyde.The advantages of using the novel constraint when rationalizing a(photo)chemical reaction are presented.