Thermophysical properties of fluids: From realistic to simple models and their applications

Recent systematic and extensive computer simulations on realistic models of polar and associating fluids have shown that the long-range interactions have only marginal effect on the properties of these fluids. This finding leads to short-range models upon which a perturbation theory may be developed. An attempt to develop a methodology to construct such models (called primitive models) directly from the parent realistic models without resorting to (or reducing at least to minimum) ad hoc adjustments is presented and exemplified by constructing models of methanol, water, and carbon dioxide. It is shown that the structural properties of the primitive model fluids obtained by means of purely theoretical considerations compare well with those of their realistic counterparts.