Theory of the electron affinity of clusters of rare-gas atoms

Abstract

The electron affinity of small clusters of rare-gas atoms like ${\mathrm{Ar}}_{\mathrm{n}}$, ${\mathrm{Kr}}_{\mathrm{n}}$, and ${\mathrm{Xe}}_{\mathrm{n}}$ is calculated using a dielectric continuum model. Thus, we obtain for ${\mathrm{Xe}}_{\mathrm{n}}$ a positive electron affinity for approximately n>10. For small clusters (n≃12) the excess electron is only weakly bound in a diffuse orbital. For larger clusters (n>25) we conclude that ${\mathrm{Xe}}_{\mathrm{n}}^{\mathrm{-}}$ is very stable. The clusters ${\mathrm{Kr}}_{\mathrm{n}}^{\mathrm{-}}$ and ${\mathrm{Ar}}_{\mathrm{n}}^{\mathrm{-}}$ are strongly stable only when they are much larger (n>100).