The stabilized jellium model is a simple modification of the jellium model, which more realistically describes simple metals of high density, such as Al, Ga, Pb, etc. We analyzed the fragmentation processes of charged spherical A1 clusters in the framework of the stabilized jellium model. Kohn-Sham calculations of the parents and daughters, using the local density approximation, have been made. We evaluated the dissociation energies of AIL, AI;?, and Al,, with N = 1-30 atoms, in all possible decay channels. We discuss the most favorable decay channels, which are ruled by the shell structure (magic numbers of valence electrons in the parents and the daughters) oscillations around an average trend given by a liquid drop model. We compare our calculations with others and with the available experimental data. 0 1995 John Wiley & Sons, Inc.
. Introductionn previous works, the surface and cohesive I properties of bulk-stabilized jellium and the energetics of small stabilized jellium clusters were studied [l-41. In this work, we studied the decay of charged aluminum clusters containing up to 30 atoms within the stabilized jellium model. The stabilized jellium model retains the simplicity and universality of the jellium model, widely used in cluster physics. Both are simple in the sense that the ions are replaced by a continuous charge background and universal in the sense that the only input parameters are the density parameter r , (the ionic charge density is n = 3/47~r,', for disInternational Journal of Quantum Chemistry, Vol. 56, 239-246 (1995) 9 1995 John Wiley 8, Sons, Inc. tances smaller than the cluster radius R = r, N,f'3, with N , the number of valence electrons of the neutral cluster) and the valence ; . The stabilized jellium model cures some deficiencies of the jellium model: unrealistic binding energies at all densities, unrealistic bulk moduli at low densities, and unrealistic surface energies at high densities. All these results follow from the instability of jellium at densities different from r , = 4.00 bohr. In the stabilized jellium model, which is clearly more realistic than is jellium for A1 (which has r , = 2.07 bohr and z = 3), we add to the electrostatic potential inside the cluster a constant potential, different for each metal, and constructed in order to have stability of the bulk metal at the observed density.