Molecular dynamics studies of properties of supercritical fluids

This work involves the determination of transport coefficients and equation of state of supercritical fluids by equilibrium molecular dynamics (MD) simulations on parallel computers using the Green-Kubo formulas and the virial equation of state, respectively. The MD program uses the effective Lennard-Jones potential, linked-cell lists for efficient sorting of molecules, periodic boundary conditions, and a modified velocity Verlet algorithm for particle displacement. Simulations have been carried out on pure oxygen at various supercritical conditions, with shear viscosity and thermal conductivity coefficients, and pressures computed for most of the conditions. Preliminary results compare well with experimental and the National Institute of Standards and Technology (experimental) results. Results show that the number of molecules and the potential cutoff radius have no significant effect on the computed coefficients, while long-time integrations are necessary for accurate determination of the coefficients.