Theory of Universal and Nonuniversal Quantities at the Critical Point of a Fluid

Abstract

The hierarchical reference theory of fluids is truncated at the first equation with an Ornstein-Zernike ansatz for the correlation function and solved for the hard-sphere interaction plus an attractive well. Starting fom the Percus-Yevick hard-sphere result the solution flows to the fixed point given by the asymptotic analysis with exponents γ = 2ν = 1.378. The nonuniversal quantities and the crossover to the noncritical region has been computed and excellent agreement is found with the measured PVT and specific-heat data of argon in the preasymptotic region.