Polar hard dumbbells

The Helmholtz free energy A of the polar hard dumbbell system is given by /I = Ao + AA where /Iq is the hard core contribution and A A is the electrostatic contribution. The electrostatic contribution AA can be calculated using a charging technique... 

This approach has been used ° to map out the phase diagram (coexistence and spinodal curves) for the polar hard dumbbell fluid at L = 0.5. The major conclusion from this work is that the critical point, due to electrostatic interactions alone, is at a much lower temperature than the critical point of a corresponding real fluid. Thus, electrostatic interactions are a small perturbation to the thermodynamics of the Lennard-Jones interaction. 

These same techniques can be applied to polar/nonpolar fluid mixtures where the polar species is the polar hard dumbbell. In this case, the internal... 

The analytic solution of the SSOZ-MSA equation for polar hard dumbbells came before any serious consideration was given to calculating the dielectric constants of such systems by computer simulation. At the time, there was considerable controversy about the simulation methods used to calculate the dielectric constant, and for the model systems then in vogue (dipolar hard spheres and the Stockmayer fluid) there was also debate about the correct value of the dielectric constant. Today, this problem is becoming better understood in particular, the quality of the simulation work has improved greatly, and this has allowed meaningful conclusions to be drawn about the relative merits of simulation methods. 

The first calculations of the dielectric constant for fluids with shape forces were the polar hard dumbbell results of Morriss et al. ° ° These simulations... 

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