Computation of partial enthalpies of various Lennard-Jones model mixtures by NPT molecular dynamics

Abstract

Exact calculation of the thermal diffusion coefficient, DT, of a binary mixture by molecular dynamics requires a separate determination of the partial enthalpies. A recently proposed method is used here to evaluate these quantities for Lennard-Jones binary liquid mixtures of which the component particles interact via very different pair potential functions. It is shown that the method works well for the 'nonideal' mixtures considered. The 'exact' values of the partial enthalpies deviate significantly from those approximated by sharing the total enthalpy among the components proportionally to the composition. Thus the values of DT recently computed for these mixtures have to be corrected appreciably, as expected.