Analytical derivatives for geometry optimization in solvation continuum models. I. Theory

We report in this article a way to compute analytical derivatives for geometry optimization in solvation continuum models. This method can be applied to Molecular Mechanics as well as Quantum Chemistry calculations and is both simpler to implement and more powerful than other derivation methods used so far. Extensions to the cases when the solvent is either an ionic solution described by the linearized Poisson-Boltzmann equation or an anisotropic medium with a tensorial dielectric permittivity are discussed.