A New Intermolecular Potential Model for the n- Alkane Homologous Series

A new model for the n-alkane homologous series has been developed, param-eterized to the vapor-liquid coexistence properties for a range of chain lengths. The model utilizes the Buckingham exponential-6 potential to describe the non-bonded interaction energy. Histogram reweighting grand canonical Monte Carlo methods were used to determine the model parameters. The new model repro-duces the experimental saturated liquid and vapor densities and vapor pressure for ethane through octane to within average errors of 0.5%, 2.1 % and 2.2 % re-spectively. Critical temperatures and densities were also found to be in good agreement with experiment. Critical pressures are slightly overestimated for longer chain lengths. Comparisons were made to the TraPPE [J. Phys. Chem.