Critical phenomena of the Lennard-Jones fluid on the basis of perturbation theories

Abstract

The critical region of the Lennard-Jones (LJ) fluid is studied using the compressibility relation together with the optimised random-phase approximation for the radial distribution function. The long-range tail of the interatomic interaction introduces strong logarithmic corrections to the leading term of the isothermal compressibility and only for t=(T-Tc)/Tc<or approximately=10-4 does one find the expected spherical-model critical behaviour. The authors reinterpret, in exactly the same way, their previous results which were obtained with the iterative perturbative method used with the EXP approximation.