RESONANT X-RAY-ABSORPTION OF NEON CLUSTERS - THE INFLUENCE OF CLUSTER-SIZE ON THE CHARACTER OF CORE-EXCITED STATES

First resonant K-shell absorption spectra of atomic clusters covering the size range from the atom to the solid are reported. Discrete absor ption into Rydberg states as well as the near edge ionization continuu m (XANES/EXAFS) of neon clusters (N almost-equal-to 15-4000) is invest igated with excellent spectral resolution. Shifts and splittings of th e absorption features (1s --> 3p, 4p) provide information on local pro perties of the different atomic sites. Besides identifying surface and bulk contributions we observe how die character of a transition chang es from a Rydberg orbital in a small cluster into a bulk excitation in larger systems.