ELECTRONIC STATES AND STABILITY OF SELENIUM CLUSTERS

Electronic structures and stability of Se-n (n=3,4,5,6,7,8) dusters ha ve been studied by using the discrete variational method in the framew ork of the local-density approximation. Binding energy, ionization pot ential, affinity energy, and other electronic properties using the str ucture models of Hohl et al. [Chem. Phys. Lett. 139, 540 (1987)] are p resented and compared with the available experiments. In addition, a r ectangular lattice arrangement of selenium clusters has been fabricate d on highly oriented pyrolytic graphite, and examined by the scanning tunnel microscope image which was found to consist of a 0.72 X 0.85 nm (2) lattice spacing with individual molecules of 0.53+/-0.05 nm in dia meter. Theoretical calculations reproduce well the experimental observ ations.