Derivation of Distributed Models of Atomic Polarizability for Molecular Simulations

The main thrust of this investigation is the development of models of distributed atomic polarizabilities for the treatment of induction effects in molecular mechanics simulations. The models are obtained within the framework of the induced dipole theory by fitting the induction energies computed via a fast but accurate MP2/Sadlej-adjusted perturbational approach in a grid of points surrounding the molecule. Particular care is paid in the examination of the atomic quantities obtained from models of implicitly and explicitly interacting polarizabilities. Appropriateness and accuracy of the distributed models are assessed by comparing the molecular polarizabilities recovered from the models and those obtained experimentally and from MP2/Sadlej calculations. The behavior of the models is further explored by computing the polarization energy for aromatic compounds in the context of cation-π interactions and for selected neutral compounds in a TIP3P aqueous environment. The present results suggest that the computational strategy described here constitutes a very effective tool for the development of distributed models of atomic polarizabilities and can be used in the generation of new polarizable force fields.