Molecular Dynamics and ab initio Molecular dynamics

The aim of molecular dynamics is to model the detailed microscopic dynamical behavior of many different types of systems as found in chemistry, physics or biology. The history of molecular dynamics goes back to the mid 1950's when first computer simulations on simple systems were performed [11]. Excellent modern textbooks [12,13] on this topic can be found and collections of articles from summer schools are a very good source for in depth information on more specialized aspects [14,15,16].

Molecular Dynamics is a technique to investigate equilibrium and transport properties of many-body systems. The nuclear motion of the particles is modelled using the laws of classical mechanics. This is a very good approximation for molecular systems as long as the properties studied are not related to the motion of light atoms (i.e. hydrogen) or vibrations with a frequency $\nu$ such that $h \nu > k_{B} T$ . Extensions to classical molecular dynamics to incorporate quantum effects or full quantum dynamics (see for example Refs. [17,18] for a starting point) is beyond the scope of this theory section.