30min:
FIRST PRINCIPLES DYNAMICS AROUND CONICAL INTERSECTIONS: THE ROLE OF THE ENVIRONMENT AND INTERSECTION TOPOGRAPHY.

TODD J. MARTINEZ, Department of Chemistry, Stanford University, Stanford, CA.

We discuss some recent examples, drawn from small molecules and chromophores in solvated/protein environments, of excited state dynamics using the ab initio multiple spawning method. We explore the role of the environment in altering the energetics of conical intersections and/or their topography, e.g. sloped vs peaked. A first attempt at a rate theory incorporating these aspects will be presented and compared to dynamics results. A key question which we comment on is the number of degrees of freedom which should be required in such a rate model. Is a single reaction coordinate sufficient, or are conical intersection dynamics inextricably multi-dimensional?