EFFECTS OF THE CLUSTER-SURFACE ON THE ELECTRONIC SHELL STRUCTURE - FACETING, ROUGHNESS AND SOFTNESS

Several simple models have been used to study the effects of the surfa ce on the electronic shell structure in metal clusters. The main resul ts are as follows: The icosahedral clusters have the same electronic s hell structure as the sphere up to about 1000 atoms. The surface rough ness causes the distribution of the level spacings to be a Wigner dist ribution. By varying the softness of the potential we can obtain poten tials where the simplest classical orbits are the 'five-point star' or even the 'three-point star'.