EFFECT OF THE ATTRACTIVE FORCES ON THE DENSITY CHANGE MELTING OF 2D LJ FLUIDS

The Weeks-Chandler-Andersen perturbation theory of fluids can be consi dered as a modern version of van der Waals'. Whereas in the old van de r Waals theory the effect of the attractive forces on the thermodynami c properties is introduced through a constant, a, in Weeks-Chandler-An dersen theory this constant is replaced by a function of temperature a nd density alpha(beta, rho). This function has been determined by mean s of Molecular Dynamics simulation of a two-dimensional Lennard-Jones fluid, and here is used to analyse the effect of attractive forces on the density change in melting. The influence is found to be slightly g reater than the predictions of van der Waals theory.