BOUND DELOCALIZED EXCITED-STATES IN I-XEN CLUSTERS

By combining photoelectron spectra and photodetachment action spectra of I-Xen clusters (n = 1-12), we have identified bound extended excite d electronic states. The critical size to the binding of such states i s n > 4-5. The spatial confinement and the binding energy of the excit ed stales increase monotonously with the cluster size. We discuss the analogy between these bound electronic states and the binding of exces s electrons in the Xe-n(-) clusters. This study introduces a new metho dology for the investigation of empty bands in clusters, residing abov e or below the vacuum level, via the excitation of slightly perturbing impurity states.