POTENTIAL-ENERGY SURFACES OF SODIUM CLUSTERS WITH QUADRUPOLE, HEXADECAPOLE, AND TRIAXIAL DEFORMATIONS

Combining a modified Nilsson-Clemenger model with the shell-correction method, the potential-energy surfaces of sodium clusters with sizes of up to N = 200 atoms are calculated, including nonaxial deformations. For spherical clusters, the model potential is fitted to the single-particle spectra obtained from microscopically self-consistent Kohn-Sham calculations using the jellium model and the localdensity approximation. Employing the Strutinsky shell-correction method, the surface energy of the jellium model is renormalized to its experimental value. The ground-state shapes are determined by simultaneous minimization of the deformation energies for quadrupole, hexadecapole, and triaxial cluster deformations.