Metastable Lennard-Jones fluids. III. Bulk viscosity

The method of equilibrium molecular-dynamics simulation in combination with the Green-Kubo formula has been used to calculate the bulk viscosity of a Lennard-Jones fluid. Calculations have been made at temperatures 0.4 ≤ k(B)T/ɛ ≤ 2.0 and densities 0.0075 ≤ ρσ(3) ≤ 1.2 at 116 stable and 106 metastable states of liquid and gas. The depth of penetration into the region of metastable states was limited by spontaneous nucleation. In the region of stable states the data obtained are compared with the results of previous investigations. It has been established that the system transition across the lines of liquid-gas and liquid-crystal phase equilibrium and penetration into the metastable regions of liquid and gas are connected with increasing bulk viscosity. The behavior of bulk viscosity close to the spinodal of a superheated liquid and supersaturated vapor is discussed.