PUB - Publikationen an der Universität Bielefeld

Direct molecular dynamics simulations of multiatomic systems, such as adsorbed atoms or clusters on crystalline surface, surface-atom scattering, atomic friction, etc., are known to have severe time-scale and size limitations. Therefore, an alternative approach based on Langevin dynamics is often used. In this work, we derive the generalized Langevin equation for a system in contact with a heat bath. In contrast to the previous treatments focusing on linear system-bath coupling, we consider a general case where the corresponding interaction potential has an arbitrary functional form, but is weak in comparison to the coupling between the bath particles. The validity of our results is demonstrated on two simple models.