Extensions to More Complex Potentials and Molecules

Abstract

So far, only pair potentials were used in the previous simulations. In this chapter, we now consider several applications which need more complex potentials , and we discuss the necessary changes in the algorithms. We start with three examples for many-body potentials, the potential of Finnis and Sinclair [232, 330, 593], the EAM potential [64, 173, 174], and the potential of Brenner [122]. The Finnis-Sinclair potential and the EAM potential describe metallic bonds. We use these potentials to simulate microcracks and structural changes in metallic materials. The Brenner potential describes hydrocarbon bonds. We employ it in the simulation of carbon nanotubes and carbon buckyballs. Furthermore, we extend our code to potentials with fixed bond structures. We then simulate simple networks of atoms and chain molecules such as alkanes and polymers. Finally, we give an outlook on the implementation of more complex biomolecules and proteins.