Theory and atomistic simulation of krypton fluid

Abstract

An ab initio interaction potential available in literature is scaled via an empirical procedure and used in an extensive computer simulation study to investigate the thermodynamic properties and self-diffusion coefficient of krypton over a wide range of densities and temperatures. The thermodynamic properties of the fluid phase equilibriums are computed utilizing the Gibbs ensemble Monte Carlo simulation technique. The equation of state and the pair correlation function are obtained using the NVT-Monte Carlo simulation method. The time-correlation function formalism of Green-Kubo is applied in molecular dynamics simulations to calculate the self-diffusion coefficient. Furthermore, the modified Cohen-Turnbull theory is employed to determine the self-diffusion coefficient and the mean free volume needed for this purpose is provided via the generic van der Waals theory. The virial minimization method is used to compute the effective diameter and the results are applied within the generic van der Waals theory as the repulsion-attraction splitting distance of the interaction potential. A remarkable agreement is observed between the computed and empirical results for the orthobaric densities, the vapor pressure, the critical point, and the equation of state. A detailed analysis is presented for the calculated self-diffusion coefficient.