Calculation of partial enthalpies of an argon-krypton mixture by NPT molecular dynamics

Abstract

In an earlier paper, we have indicated how, by using a particle-insertion technique, partial molar enthalpies and related quantities can be evaluated from simulations on a single state point. In the present paper we apply this method to a Lennard-Jones argon-krypton mixture. For this particular model system, we find that the present method yields partial enthalpies and volumes with the same accuracy as the existing (numerical differentiation) method. However, the present method is superior in determining differences in partial molar quantities, including the excess Gibbs free energy. Finally, we discuss the relation between the thermodynamic partial molar enthalpy and a related, but distinct microscopic quantity, which has been introduced in the definition of the heat current in a number of molecular dynamics studies of thermal transport in mixtures.