Fluctuation Theory of Mixtures (A Statistical Mechanical Background)

The statistical mechanical basis of the fluctuation theory of mixtures is reviewed. An overview of the statistical mechanical relations between the microscopic properties of a system and its macroscopic properties is presented. The distribution functions in equilibrium systems are defined and relations between the distribution functions and thermodynamic properties for pure fluids and fluid mixtures are reported. The available approximations to distribution functions are presented. Definitions of direct correlation functions, direct correlation function integrals, and their relations with fluctuation integrals are reported.