Orbits in Large Aluminum Clusters: Five-Pointed Stars
  The distinctions in the mass spectra of large sodium (Na_N) and aluminum (Al_N) clusters are discussed. A semiclassical method is used to describe the shell effects within a spherical jellium model. It allows one to analyze the relative role of different classical trajectories in the formation of electronic supershells in clusters of various sizes at zero and finite temperatures. A criterion for the hardness of the self-consistent potential is formulated. The conjecture that the five-point-star trajectories make the main contribution to the spectral oscillations for large soft-potential Al_N (250<N<900) clusters is substantiated. The computational results are in agreement with the mass spectra of the Al_N clusters at T ~ 300 K. 
G.V.Shpatakovskaya