Fast evaluation of induction energies: a second-order perturbation theory approach

A fast and inexpensive approach for determining induction energies based on second-order perturbation theory is investigated. Variational and perturbational induction energies resulting from the interaction of a unit point charge with a given chemical compound are compared. The interaction energies have been computed at the second-order Moller-Plesset (MP2) and the Hartree-Fock (HF) levels, using the ELF and the 6-311++G(d,p) basis sets. After appropriate scaling, the perturbative, HF induction energies reproduce the reference, MP2 quantities. This inexpensive, yet efficient, strategy, involving only a single HF computation, can be employed to generate rapidly large grids of induction energies, and, therefore, to develop non-additive force fields. (C) 2000 Elsevier Science B.V. All rights reserved.