Interstitial Sublattice Research Articles

Equation of State for Vapor-Liquid-Solid System

Generalizing the idea of order-disorder in the alloy theory, we can calculate the unified equation of state for a lattice gas with many interstitial sublattices in the degree of approximation similar to that developed by Bragg-Williams. For n =9 ( n is the number of sublattices), the concrete equation of state is estimated and the ratio of the number of molecules belonging to each sublattice to their total number is given as a function of molecular density. Then the critical temperature and density for vapor-liquid transition are estimated for n =4, 9, 16. Furthermore, it is shown that the density region in the stable liquid phase is very narrow for n =4, but that it becomes wider for n =9, 16.

A Theory of Cooperative Phenomena. II. Equation of States for Classical Statistics

A method of obtaining the equation of state of a classical assembly through the solid, liquid, and gas phases based on the order-disorder concept is explained. At first, the method is illustrated on an imaginary two-dimensional model. Next, the general procedure to increase the number of interstitial sublattices to infinity is explained for a one-, two-, and three-dimensional lattice. In the one-dimensional case, the present method proves to be identical with Gürsey's rigorous solution. An approximate treatment for the solid state is added.