Spectral Properties of Confined Atoms.

The changes in energy and photoionization spectra of atoms upon confinement by a spherical environment are explored theoretically. Two kinds of confinement are considered: an endohedral confinement, such as inside the bucky-ball C[sub 60], and an impenetrable spherical confinement of adjustable radius. We demonstrate modifications in the energy spectrum and electron correlation effects in confined atoms, the appearance, nature and origin of "confinement" resonances in photoionization spectra of such atoms, as well as new regularities in the periodic table for "compressed" atoms. These findings are of importance for basic and applied physics and chemistry of atoms, molecules, surfaces, etc. [ABSTRACT FROM AUTHOR]