Analytical derivatives for geometry optimization in solvation continuum models.: II.: Numerical applications

We present some numerical applications of a new method addressed to compute analytical derivatives of free energies for continuum solvation models. The examples reported refer to quantum chemical calculations of geometry optimizations at both Hartree-Fock and Density Functional level. When implemented within the solvation method known as Integral Equation Formalism (IEF), the performances are very satisfying: the computational times of each energy gradient step are by far smaller than the corresponding values obtained with other continuum methods exploiting a different derivative approach. In addition, an increase of the accuracy whose consequence is an improvement of the convergence of gradient based geometry optimization algorithms is observed in all the analyzed molecular systems. (C) 1998 American Institute of Physics. [S0021-9606(98)50525-9].