Role of the range of intermolecular interactions in fluids

Using available realistic effective pair potentials and their variants involving forces of different range, the role of the range of interactions on the structure of pure polar and associating fluids has been investigated. Systematic computer simulations performed lead to the unambiguous conclusion that the structural properties of both types of fluids are governed by the same molecular mechanism as normal fluids, i.e. by the short-range interactions, whereas the long-range part of electrostatic forces, regardless of their strength, plays only a marginal role and may be treated as a perturbation only. Consequences of this finding and their limits are then shortly discussed.