Modified Potential Energy Surfaces

 The previous section showed that our simplest model PES captured many of the dynamical effects commonly seen in finite systems such as proteins and clusters. Here we seek to modify the standard PES to understand which factors influence a system's ability to find the global minimum. The model PES has too many parameters to allow a systematic study of the whole parameter space. Additional complexity could, of course, be generated by making the parameters functions of l. The effects of varying some of the parameters, though, are fairly obvious. For example, increasing $\sigma$ would make all the rates $\sigma$ times faster. Our approach here is to make only changes to the PES that leave the basic thermodynamics unchanged--i.e. we keep E_f constant--and to concentrate on the factors that could lead to particularly interesting behaviour.