The SP-MC computer simulation method for calculating the chemical potential of the square-well fluid

Abstract

The efficient recently proposed SP-MC method for calculating the chemical potential of hardbody fluids at very high densities by computer simulation is extended to the case of the squarewell fluid. Results are obtained for the square-well fluid with energy width parameter λ = 1.5. The implementation of the method takes into account a discontinuity in the third derivative with respect to core size of the chemical potential at infinite dilution of a test particle in the fluid. We note the implications of this discontinuity for the SP-MC method for larger values of λ and for equations of state for square-well fluid mixtures. Chemical potentials have been simulated at two high densities over a range of temperatures. We additionally present new simulation results for the compressibility factor and the internal energies of the fluid at these state points, and perform thermodynamic consistency calculations involving these quantities and the chemical potentials. The results are also compared with those of a recently-published equation of state.