Mixture-model approach to the theory of classical fluids

A family of distribution functions is denned for a classical fluid. Interpretation of these distribution functions as mole fractions of quasicomponents suggests that a one-component fluid may rigorously be viewed as a mixture of any number of components. It is suggested that a detailed study of these "quasicomponent distribution functions" may be useful in gaining insight into the way an extensive thermodynamic quantity is "spread" over the various "species." Some bearings on the existing theories of liquid water are discussed, and it is concluded that the so-called "continuous" and "mixture-model" approaches to the theory of liquid water are equivalent from the formal point of view.