Table of Contents
Advances in Physical Chemistry
Volume 2012, Article ID 268124, 13 pages
Review Article

Exploring Multiple Potential Energy Surfaces: Photochemistry of Small Carbonyl Compounds

1The Hakubi Center, Kyoto University, Kyoto 606-8302, Japan
2Fukui Institute for Fundamental Chemistry, Kyoto University, Kyoto 606-8103, Japan
3Toyota Physical and Chemical Research Institute, Nagakute, Aichi 480-1192, Japan
4Department of Chemistry and The Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, GA 30322, USA

Received 20 June 2011; Accepted 9 August 2011

Academic Editor: Xinchuan Huang

Copyright © 2012 Satoshi Maeda et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


In theoretical studies of chemical reactions involving multiple potential energy surfaces (PESs) such as photochemical reactions, seams of intersection among the PESs often complicate the analysis. In this paper, we review our recipe for exploring multiple PESs by using an automated reaction path search method which has previously been applied to single PESs. Although any such methods for single PESs can be employed in the recipe, the global reaction route mapping (GRRM) method was employed in this study. By combining GRRM with the proposed recipe, all critical regions, that is, transition states, conical intersections, intersection seams, and local minima, associated with multiple PESs, can be explored automatically. As illustrative examples, applications to photochemistry of formaldehyde and acetone are described. In these examples as well as in recent applications to other systems, the present approach led to discovery of many unexpected nonadiabatic pathways, by which some complicated experimental data have been explained very clearly.