VAPOR-LIQUID-EQUILIBRIA FOR STOCKMAYER FLUIDS WITH RIGID AND POLARIZABLE DIPOLES

Vapour-liquid equilibria for polarizable and non-polarizable Stockmaye r fluids have been calculated using a recently introduced improved ren ormalized perturbation theory. Up to mu(2) = 3, the predicted results for a Stockmayer fluid are in good to excellent agreement with those from an equation of state and from simulations. Wertheim's renormaliza tion procedure for the dipole moment is applied to account properly fo r the many-body inductive interaction forces in polarizable dipolar fl uids. The influence of an isotropic and anisotropic polarizability ten sor alpha on the predicted phase equilibria and heat of vaporization i s discussed. Inductive interactions are shown to play an essential rol e in understanding the phase behaviour of polar fluids.