Estudo comparativo das propriedades de sistemas simples pelas técnicas de dinâmica molecular e Monte Carlo

Abstract

The Lennard-Jones model of molecular interaction is one of the most used in computer simulations of molecular systems, because it is a a simple model that reproduces experimental results with excellent agreement. We use the Lennard-Jones model to perform simulations of monoatomic systems, in the canonical ensemble, using two of the main simulationals techniques: Monte Carlo and Molecular Dynamics. Based on the theorical equivalence between these methods, we perform a comparative study between results obtained with each method. We focus on quantities that determine thermodynamic and structural properties of the system in the solid and fluid phases, as well as close to the melting temperature. We perform simulations of monoatomic systems consisting of two kind of atoms, which interact through a modified species-dependent Lennard-Jones potential. We study, with both techniques, the structural configurations presented by this system as a function of the temperature and the interaction energy scale of the different kinds of atoms.