IRD from a Conical Intersection

We have already seen that a conical intersection forms a bottleneck separating the excited-state branch of a nonadia-batic photochemical reaction path from the ground-state branch. The nature of the products generated after decay at an intersection will depend on the corresponding ground-state valleys (reaction paths) that can be accessed from the conical 

In the following we will outline how the IRD method is used to locate IRDs and, consequently, GSRPs starting at the 

and the structures Mi, Mg, TS12, and TSgi can be characterized in terms of the intersecting electronic states as discussed there.) 

The elliptic cone model of the potential energy surface at a conical intersection point discussed above is not general enough to give a correct description of the relaxation in realistic molecules. First, more than two possible IRDs may originate from the tip of the cone. Second, the first-order approximation (i.e., elliptic cone) may break down at larger distances, and some IRDs may lie out of the branching plane because the real 

We will now discuss an application of the strategy described above to the radiationless decay and competitive photoproduct formation process in the cyclohexadiene (CHD)/hexatriene (HT) system. A theoretical study of the first singlet excited state (2Aj) of cZc-hexa-l,3,5-triene (cZc-HT) 

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