Fluids of pseudo-hard bodies II. Reference models for water,methanol, and ammonia

Pseudo-hard body fluids resulting from extended primitive models of water, methanol, and ammonia have been investigated both by computer simulations and theory for a number of geometrical parameters. It is shown that none of the existing equations of state and integral equations for the site-site correlation functions is able to describe the properties of the pseudohard body fluids reasonably accurately. For the equation of state an accurate semi-empirical method is proposed and for the site-site correlation functions the reference average Mayer function perturbation theory has been found to perform at least qualitatively correctly, which is not the case with Ornstein-Zernike equation based theories.