Bonding properties of mercury dimers in the pseudopotential local-density-approximation scheme

Bonding properties of the mercury dimers ${\mathrm{Hg}}_2$ and ${\mathrm{Hg}}_2^{+}$ are investigated with accurate computations carried out in the density-functional local-density-approximation (LDA) scheme, within the pseudopotential framework. Our calculation accounts for several characteristic properties of these molecules, without, however, full quantitative agreement with experiment. Nevertheless, we argue that the pseudopotential LDA scheme provides a suitable model to study the size evolution in the electronic structure of mercury clusters. Furthermore, the investigation of such systems containing a large number of atoms may be simplified by including in the valence charge the 6s electrons only, and properly taking into account the short-range repulsion of the filled 5d shells.