Size effects in the electronic properties of hydrogen and helium embedded in small metal clusters: The self-consistent spherical-jellium-particle model

The electronic properties of H and He, as the simplest examples for reactive and inert atomic systems embedded in small metal clusters, are investigated within the self-consistent spherical-jellium-particle model. Physical properties of interest are the modification of the electronic properties of the jellium particle (as a model for real clusters of the sp-bonded metals) by light impurities and vice versa, the modification of the free-atom properties when the atom is embedded in a metallic host which exhibits size-dependent quantum-mechanical properties. Quantities investigated include size-dependent impurity ionization potentials, relaxation shifts and static screening properties, size-dependent impurity immersion energies, and size-dependent impurity-induced quenching of the collective modes in small metal particles. Among other predictions it is demonstrated how the so-called magic numbers are modified by impurity embedding. The experimental verification of these predictions could give additional evidence for the electronic shell model for these particles.