AN ACCURATE EQUATION OF STATE FOR THE EXPONENTIAL-6 FLUID APPLIED TO DENSE SUPERCRITICAL NITROGEN

The exponential-6 potential model is widely used in fluid equation of state studies. We have developed an accurate and efficient complete eq uation of state for the exponential-6 fluid based on HMSA integral equ ation theory and Monte Carlo calculations. Our equation of state has a verage fractional error of 0.2% in p V/Nk(B)T and 0.3% in the excess e nergy U-ex/Nk(B)T. This is a substantial improvement in accuracy over perturbation methods, which are typically used in treatments of dense fluid equations of state. We have applied our equation of state to the problem of dense supercritical N-2. We and that we are able to accura tely reproduce a wide range of material properties with our model, ove r a range 0.01 less than or equal to P less than or equal to 100 GPa a nd 298 less than or equal to T less than or equal to 15000 K. [S0021-9 606(98)50841-0].