The Polarizable Continuum Model (PCM) is a well established framework to describe various kinds of solvation interactions implicitly within a quantum chemical calculation. The foundation of PCM is the extension of the molecular vacuum Hamiltonian Ĥ0 with a new term Vel , describing the Coulomb interaction of the electrons of the solute and a solvent charge density located outside the solute cavity C, thus allowing the calculation of the free energy of the solute, G el , as