An introductory overview of action-derived molecular dynamics for multiple time-scale simulations

In this introductory paper, we briefly review the action-derived molecular dynamics (ADMD) that has recently been developed for the atomistic simulation of infrequent-event systems such as surface diffusion process and complex molecular formation. The method is specifically designed to find a dynamical trajectory when the final atomic configuration is given as a priori. ADMD has its theoretical foundation in the least action principles. According to the formulation, the most probable dynamical trajectory connecting the initial and final atomic configurations, is determined through minimizing an appropriate object function that is derived from the classical action by imposing dynamical conditions as required as the conservations of total energy. It thus enables us to find the actual dynamical path of the systems. which is a distinguishing feature compared with other similar methods such as the nudged elastic band method. In this paper, we present our recent simulation results using ADMD, as well as an introduction to its theoretical background and enhanced algorithms. (C) 2004 Elsevier B.V. All rights reserved.