Potential energy factor, model

In this section we focused our attention to a rationalization of the factors determining the stereoselectivity through ab initio mixed quantum/classical (QM/MM) Car-Parrinello molecular dynamic simulations. We have used the same basic computational approach used in Section 3 to explore the potential energy surface of the reaction. Since the catalyst system, 1, is relatively large, we have used the combined QM/MM model system B as shown in Figure 3 and described in subsections 2.1 and 3.1. 

The frequency factor, v, should be on the order of the lattice vibrational frequency, or 1013 s-1. The extreme simplicity of the model makes it very convenient for many applications. This theoretical model is now generally referred to as the image-hump model, or the Schottky-hump model, of field desorption. The potential energy curve of this model is not defined at all distances because of the crude nature of the argument it is nevertheless shown schematically in Fig. 2.9(a).48... 

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