Abstract:

The role of the intersection between two potential energy surfaces has been more generally emphasizing on than before.In the present system,the intersections between S1,T1 and S0 surfaces were optimized with the state-averaged CAS(8,7)/6-31G method.The comparison of their optimized structures demonstrates that the intersection points of S1/S0 and S1/T1 locate in the same region,referred to as S1/T1/S0 point.The existence of S1/T1/S0 point and its high possibility of radiationless transition via intersystem crossing or internal conversion,would make the system have the most efficient funnel to generate the ground-and triplet-state products,which is consistent with the experimental facts.

Key words: Cyclobutanone, S₁/T₁/S₀ intersection point, Photochemical reaction