Anions of Xenon Clusters Bound by Long-Range Electron Correlations

In contrast with the single atom, atomic van der Waals clusters can form stable anions where the excess electron is bound due to long-range correlations with the electrons of the cluster. We report on extensive all-electron many-body ab initio studies on Xe clusters. Three-dimensional, planar, and linear structures of the clusters are investigated and compared. In particular, we find that the minimal number of Xe atoms in the cluster required to form a stable anion is 5 independently of the dimensionality of the cluster. We provide electron affinities for clusters made of 5, 6, and 7 atoms in all dimensions and find that the planar clusters form the most stable anions. The Dyson orbitals of the excess electrons are computed and analyzed.

Figure 1

Properties of the Xe clusters of different dimensionalities with 4 (a), 5 (b), 6 (c), and 7 (d) atoms. The clusters are shown by atomic spheres connected by bonds, with the radii of the spheres being 1.08 Å (half of the van der Waals radius of Xe). Indicated above each cluster are the electron affinities (EA), and the numbers given in brackets below each cluster are the internuclear separations in angstroms.

Figure 2

Electron density of the Dyson orbital of the attached electron along selected axes for the ${\mathrm{Xe}}_6^{-}$ clusters of different dimensionalities. The centers of the axes coincide with the centers of the clusters.