Alternative Approaches for the Calculation of Induction Energies: Characterization, Effectiveness, and Pitfalls

One of the practical difficulties precluding the generalized development of nonadditive, polarizable models for statistical simulations is rooted in the costly estimation of accurate induction energies, from which distributed polarizabilities can be derived. From a finite perturbation (FP) perspective, mapping the induction energy over a grid of points implies as many distinct quantum chemical calculations of the molecule interacting with a polarizing charge as the total number of points. Here, two alternative routes for computing accurate induction energies in a time-bound fashion are explored. The first one is based upon second-order perturbation theory and only involves a single quantum chemical calculation at the Hartree−Fock level of approximation to map the induction energy. The second one, less straightforward in its implementation, relies on a topological partitioning of the response charge density, also evaluated from a single quantum chemical calculation, yet at virtually any level of sophistica...