SSOZ-HNC AND SSOZ-PY INTEGRAL-EQUATION STUDIES OF THE STRUCTURE OF 3-SITE POLAR FLUIDS

Abstract

Structure factors and site-site distribution functions for models of liquid carbon disulphide (CS2) and acetonitrile (CH3CN) are obtained by using the site-site Ornstein-Zernike (SSOZ) integral equation with the Percus-Yevick (PY) and the hypernetted chain (HNC) closures. The calculated structure factors are found to be in good agreement with the neutron and X-ray diffraction data as well as with the simulation data. The site charges have a significant effect on the distribution functions but not on the structure factors of both the systems. There is very good qualitative agreement between the calculated distribution functions and the results from computer simulations. Distinctive shoulders found in the simulation results for the first peaks of the C-N and CH3-CH3 distribution functions are enhanced in the calculations using the integral equations.