Potential models
All of the non-bonded (van der Waals and Coulomb) and each of the bonded interactions are collected together in a potential model or a forcefield. These are usually a file or files that contain all of the information required to calculate the potential energy for the given system in any structural configuration. It was previously the case that a whole PhD project may be focused on the development of a potential model. However, as we shall see, there are now libraries of potential models that may be used by anyone that only require a small amount of development.