An improved potential model for n-hexadecane molecular dynamics simulations under extreme conditions

A potential model is proposed and used in equilibrium and non-equilibrium molecular dynamics simulations of n-hexadecane at high temperatures and pressures. The model is an extension of the Ryckaert and Bellemans model with added intramolecular terms and modified intermolecular parameters. The latter were modified to ensure that the values of selected thermodynamic parameters, calculated by equilibrium simulations, are in agreement with their corresponding experimental ones. Used in non-equilibrium simulations, the proposed model also yields more accurate viscosity values than those previously published. As a byproduct of the potential model development, the sensitivity of certain rheological parameters to values in the intermolecular parameter set is also investigated.