On the transition from Van der Waals- to metallic bonding in Hg-clusters as a function of cluster size
Year: 1988
Type: article
Abstract: The transition from insulating small Hg n clusters to metallic bulk-Hg is studied using a parametrized LCAO model. Our results for the size dependence of the cohesive energy show that covalent bonding is already important for n = 13-19, indicating that the transition from Van der Waals to covalent bonding should take place near this cluster size range. For n ≳ 80 s - and p -bands overlap, the density of states resembles the bulk density of states and the gap at the Fermi-level is close to the limiting value Δ n ( n → ∞ ) = [ N (ε F ) n ] -1 . Therefore, no important changes in the electronic structure occur for n > 80 and metallic-like optical properties similar to those observed for alkali-metal clusters are expected. For intermediate sizes (19 ≲ n ≲ 80) semiconducting like properties are expected. In qualitative agreement with experiment, we obtain for Hg-clusters an increase of the average bond-length of about 5% with respect to the bulk. The effects of electron correlations and surface relaxation are briefly discussed.
Source: Physica Scripta
Authors: G M Pastor, P Stampfli, K H Bennemann
Institution: Freie Universität Berlin
Language: English
Subfield: Physical and Theoretical Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W1978517461