  The electrostatic continuum solvent model developed by Fattebert and Gygi is
combined with a first-principles formulation of the cavitation energy based on
a natural quantum-mechanical definition for the surface of a solute. Despite
its simplicity, the cavitation contribution calculated by this approach is
found to be in remarkable agreement with that obtained by more complex
algorithms relying on a large set of parameters. Our model allows for very
efficient Car-Parrinello simulations of finite or extended systems in solution,
and demonstrates a level of accuracy as good as that of established
quantum-chemistry continuum solvent methods. We apply this approach to the
study of tetracyanoethylene dimers in dichloromethane, providing valuable
structural and dynamical insights on the dimerization phenomenon.
