Mixture-Model Approach to the Theory of Classical Fluids. II. Application to Liquid Water

The possibility of viewing liquid water as a mixture of various species is examined within the framework of classical statistical mechanics. In the first part of the paper the application of the so-called ``Two Structure Model'' to liquid water is examined. Two novel features of the present treatment are: (1) An exact classification procedure is employed to transform a one-component system into a mixture of two components. (2) No assumption as to the nature of the mixture, such as ideality, is introduced. The second part of the paper is devoted to a more generalized mixture-model formalism. Two representative examples are discussed in some detail. The first demonstrates that the volume of the Voronoi polyhedron (or Dirichlet region) of a given molecule may be viewed as the partial molar volume of certain species. The second one treats the binding energy of a molecule as part of the partial molar energy of certain other species.