Recent years have seen the extensive application of computer simulation techniques to the study of condensed phases of matter. The two techniques of major importance are the Monte Carlo method and the method of molecular dynamics. Monte Carlo methods are ways of evaluating the partition function of a many-particle system through sampling the multidimensional integral that defines it, and can be used only for the study of equilibrium quantities such as thermodynamic properties and average local structure. Molecular dynamics methods solve Newton s classical equations of motion for a system of particles placed in a box with periodic boundary conditions, and can be used to study both equilibrium and nonequilibrium properties such as time correlation functions. [Pg.271]

Due to the difficulties of QM methods to describe correctly condensed phase behavior. Van der Waals parameters and atomic point charges of molecular models are often adjusted to reproduce experimental data on macroscopic properties of the liquid state. Usually, they are fitted to thermodynamic properties determined by means of molecular dynamics (MD) or Monte Carlo (MC) simulations. [Pg.217]

The principal drawback of the DFT method is that it is computationally intensive relative to the classical adsorption models, although it is still much less compute-intensive than full Monte Carlo molecular simulation. A semianalytic adsorption model that retains computational efficiency while accounting for gas-solid potential interactions in micropores was originally proposed by Horvath and Kawazoe [12], In the Horvath-Kawazoe or HK method, a pore filling correlation is obtained by calculating the mean heat of adsorption (/> required to transfer an adsorbate molecule from the gas phase to the condensed phase in a slit pore of width // [Pg.477]

This chapter is written for the reader who would like to learn how Monte Carlo methods are used to calculate thermodynamic properties of systems at the atomic level, or to determine which advanced Monte Carlo methods might work best in their particular application. There are a number of excellent books and review articles on Monte Carlo methods, which are generally focused on condensed phases, biomolecules or electronic structure the-ory. " The purpose of this chapter is to explain and illustrate some of the special techniques that we and our colleagues have found to be particularly [Pg.1]

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