SIMULATION STUDIES ON MIXTURES OF DIPOLAR WITH NONPOLAR LINEAR-MOLECULES .2. A MIXING RULE FOR THE DIPOLAR CONTRIBUTION TO THE HELMHOLTZ ENERGY

In recent equations of state an explicit expression for the dipolar co ntribution to the Helmholtz energy F-D is used. If such equations are applied to mixtures the problem of mixing rules for F-D arises. As a s olution, a ''one-fluid dipole moment mu(x)'' is introduced which is ba sed on perturbation theory. The accuracy of the approach is tested by simulation results for mixtures of dipolar with nonpolar linear molecu les, In addition to the simulation runs from Part I (Muller et al. (19 94)), results from 97 new NVT simulations are presented. Comparisons o f pressures, internal energies, dipole energies and excess free energi es from simulations with those obtained from the equation for F-D in c ombination with the one-fluid dipole moment mu(x) shows good to excell ent agreement.