Gas-Surface Dynamics

In the preceding chapter we have been concerned with the solution of the electronic Schrodinger equation for fixed nuclear coordinates. By repeating total-energy calculations for many different nuclear configurations, energy minima and whole potential energy surfaces for chemical reactions at surfaces can be determined. However, this static information is often not sufficient to really understand how a reaction proceeds. Furthermore, in the experiment the potential energy surface (PES) is never directly measured but just reac­tion rates and probabilities. For a real understanding of a reaction mechanism a dynamical simulation has to be performed. In addition, this allows a true comparison between theory and experiment and thus provides a reliable check of the accuracy of the calculated PES on which the dynamics simulation is based.