Ab initio (Car-Parrinello) molecular dynamics (AIMD) simulations [1] are increasingly used to investigate structural, dynamical, energetic and electronic properties of biomolecules. At opposite to classical MD simulations, in this approach the underlying potential energy surface is calculated directly from first-principles. This leads to a parameter free molecular dynamics, where interatomic forces are not empirically derived, but are evaluated from electronic structure calculations as the simulations proceeds.
