Role of the reference system in study of fluid criticality by effective LGW Hamiltonian approach

Molecular fields and statistical field theory of fluids: Application to interface phenomena

Using the integral transformation, the field-theoretical Hamiltonian of the statistical field theory of fluids is obtained along with the microscopic expressions for the coefficients of the Hamiltonian. Applying this approach to the liquid-vapor interface, we derive an explicit analytical expression for the surface tension in terms of temperature, density, and parameters of the intermolecular potential. We also demonstrate that a clear physical interpretation may be given to the formal statistical field arising in the integral transformation-it may be associated with the one-body local microscopic potential. The results of the theory, lacking any ad hoc or fitting parameters are in good agreement with available simulation data.

Statistical field theory of ion–molecular solutions

Schematic representation of the multipolar molecule surrounded by salt ions in a dielectric solvent medium.