On the temperature and pressure dependences of cavities in the dielectric continuum picture

Abstract

Cavity size at equilibrium and its variations with thermodynamic conditions are studied in the dielectric continuum framework of solvents. By employing Gibbs' theory of dividing surfaces, the fluctuating cavity description of Kim [H.J. Kim, J. Chem. Phys. 105, 6818 (1996)] is extended to include effects related to the local solvent density inhomogeneity near the cavity. The resulting theory is applied to study cavity size variations with temperature and pressure in dipolar and nondipolar solvents. Model calculations show that the cavity size tends to increase with temperature along an isobar and decrease with pressure along an isotherm.