The van der Waals interactions in rare-gas dimers: the role of interparticle interactions

Abstract

We investigate the potential energy curves of rare-gas dimers with various ranges and strengths of interparticle interactions (nuclear–electron, electron–electron, and nuclear–nuclear interactions). Our investigation is based on the highly accurate coupled-cluster theory associated with those interparticle interactions. For comparison, the performances of the corresponding Hartree–Fock theory, second-order Møller–Plesset perturbation theory, and density functional theory are also investigated. Our results reveal that when the interparticle interactions retain the long-range Coulomb tails, the nature of van der Waals interactions in the rare-gas dimers remains similar. By contrast, when the interparticle interactions are sufficiently short-range, the conventional van der Waals interactions in the rare-gas dimers completely disappear, yielding purely repulsive potential energy curves.