Molecular‐Dynamics Simulation of Surface Phenomena

Abstract

Molecular‐dynamics (MD) simulation is a well‐developed numerical technique that involves the use of a suitable algorithm to solve the classical equations of motion for atoms interacting with a known interatomic potential. This method has been used for several decades now to illustrate and understand the temperature and pressure dependencies of dynamical phenomena in liquids, solids, and liquid‐solid interfaces. MD simulation techniques are also well suited for studying surface phenomena, as they provide a qualitative understanding of surface structure and dynamics. This article considers the use of MD techniques to better understand surface disorder and premelting. Specifically, it examines the temperature dependence of structure and vibrational dynamics at surfaces of face‐centered cubic (fcc) metals—mainly Ag, Cu, and Ni. It also makes contact with results from other theoretical and experimental methods. While the emphasis in this article is on metal surfaces, the MD technique has been applied over the years to a wide variety of surfaces including those of semiconductors, insulators, alloys, glasses, and simple or binary liquids. A full review of the pros and cons of the method as applied to these very interesting systems is beyond the scope of this article. However, it is worth pointing out that the success of the classical MD simulation depends to a large extent on the exactness with which the forces acting on the ion cores can be determined. On semiconductor and insulator surfaces, the success of ab initio molecular dynamics simulations has made them more suitable for such calulations, rather than classical MD simulations.