Iterative pertubative theory of the critical point of classical fluids

Abstract

The correlations of the Lennard-Jones fluid in the critical region have been computed on the basis of a generalized “exp” approximation. The perturbation theory of liquids is generalized by considering an infinite sequence of “reference” systems and the correlation functions g( r) and S( k) are obtained from a recursion relation. On the critical isocore we find the critical exponents γ = 150 ± 0.02 for the isothermal compressibility and ν = 0.78 ± 0.04 for the correlation length. This iterative perturbative approach improves considerably the results of the usual perturbation theories.