Microcanonical potential energy fluctuations and configurational density of states for nanoscale systems

Abstract

In this work, we study the distribution of potential energies for the embedded atom model (EAM), commonly associated with monoatomic metals, in nanoscopic systems of the order of tens of particles. Classical molecular dynamics simulations in the microcanonical ensemble, both in solid and liquid phases, were used to produce samples of potential energy at different total energies. We characterize the shape of these fluctuations of potential energy and, in this context, we propose a model for the configurational density of states (CDOS) capable of describing the melting phase transition of a nanoscopic system. Our results show the shape of the fluctuations outside and within the range of the solid–liquid phase transition, and demonstrate the accuracy of the CDOS model for EAM systems.