Symmetry-adapted perturbation theory for the calculation of Hartree-Fock interaction energies

Abstract

A symmetry-adapted perturbation theory is formulated for the calculation of Hartree-Fock interaction energies of closed-shell dimers. The proposed scheme leads to a basis-set-independent interpretation of the Hartree-Fock interaction energy in terms of basic concepts of the theory of intermolecular forces: electrostatics, exchange and induction. Numerical results for different geometries of HE₂, Ne₂, He-C₂H₂, He-CO, Ar-HF, (HF)₂ and (H₂O)₂ complexes show that in the region of the van der Waals minimum the proposed perturbation theory reproduces accurately the Hartree-Fock interaction energy. This fast convergence and relatively small computational cost of the proposed perturbation scheme suggest that this method is a practical alternative for the standard supermolecular approach.