Molecular damping of centrifugal barrier effects in the 3d absorption spectrum of selenium vapour

In the light of recent work on shape resonances in diatomic systems, the question of a possible persistence of atomic centrifugal barrier effects in molecules arises, particularly as regards resonant penetration of f-waves. Experiments on selenium vapour suggest that two cases may be expected depending on whether localized f states are present or not in the atom. The evidence in Se is that f waves mainly external to the atom are scattered into several channels by the anisotropic molecular field and that damping of the f-maximum results. A reason is suggested for which inner shell absorption spectra of solids may not faithfully reproduce the density of states of the conduction band, even for elemental materials.