Reaction paths synchronous transit method

The Linear Synchronous Transit (LST) method forms the geometry difference vector between the reactant and product, and locates the highest energy structure along this line. The assumption is that all variables change at the same rate along tire reaction path. 

As can be seen from the figure, the actual reaction path confirms the qualitative prediction of the Woodward-Hoffmann rules and the reaction is to be classified as concerted even if the path itself is not ideally synchronous. It is, however, interesting that despite the assynchronicity of the path the critical structure corresponding to the transition of the system from the region of the intermediate into the region of the product is quite close to the ideally symmetrical structure expected and also found by various quantum chemical methods. 

Automated transition state searching using synchronous transit-guided quasi-Newton (STQN) methods. Reaction path following using the intrinsic reaction coordinate (IRC). 

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