Prediction of the heat of mixing for binary fluids using molecular dynamics simulation

Isothermal–isobaric ensemble (NPT) molecular dynamics (MD) simulation was applied to calculate the heats of mixing for binary fluids based on an all-atom force field. The calculation protocol was tested on mixtures of 1-propanol/n-heptane, n-butylamine/n-heptane and n-butylamine/water at various temperatures and compositions. Based on a simple error analysis and comparisons of calculated and experimental data, we propose that a necessary but not sufficient condition in the predictions of the heats of mixing is to have a force field highly accurate in evaluating energetic properties for pure substances. More work is required in order to find out the sufficient conditions.