Theory for the Transition from Van Der Waals to Covalent to Metallic Mercury Clusters

The transition from van der Waals to covalent and then to metallic bonded Hg n clusters, the ionization potential I n , the s , p energy gap Δ n , the cohesive energy, and the autoionization resonance, are determined. The transition involving s -electron delocalization and s-p electronic transitions is estimated to occur for clusters having approximately (15 ÷ 20) Hg-atoms.