Dielectric behavior and multibody orientational correlations of dipolar molecular liquids

Computer simulation studies of dipolar two center Lennard-Jones molecular liquids are reported. The dielectric constant, Kirkwood factor, two and three body orientational correlation functions are given as a function of molecular elongation for a series of approximately corresponding states. The packing of linear molecules in dense dipolar liquids is found to reduce the dielectric constant by between 50% and 60% (l>0.2) from that of an equivalent Stockmayer fluid. The Kirkwood factor is found to be <1 for elongated molecules as suggested by Buckingham. These changes are explained in terms of a local structure which also predicts the qualitative features of the two and three body dipole correlation functions.