Effect of uniform electric field on homogeneous vapor-liquid nucleation and phase equilibria. II. Extended simple point charge model water

The effects of a uniform electric field on homogeneous vapor-liquid nucleation of the extended simple point charge (SPC/E) model water have been simulated. A grand canonical Monte Carlo simulation approach [I. Kusaka et al., J. Chem. Phys. 108, 3416 (1998)], which directly gives the equilibrium distribution of physical clusters, is employed to calculate the formation free energy of the SPC/E water cluster. The results show that the formation free energy is lowered in a uniform field if the chemical potential of the supersaturated vapor is fixed; in this case, the field enhances the rate of nucleation. However, if the vapor supersaturation or pressure is fixed, the formation free energy increases with the field, that is, the field reduces the rate of nucleation. This conclusion is consistent with an earlier study using the i/v cluster theory for weakly dipolar Stockmayer fluid in a uniform field (Part I). A byproduct of this work is the vapor-liquid coexistence (binodal) of the SPC/E water in the presence of the electric field. (C) 1999 American Institute of Physics. [S0021-9606(99)50605-3].