General axial shapes of sodium clusters

The shell correction method is applied to calculate the shapes and binding energies of Na clusters. The axial equilibrium shapes are calculated by minimizing five deformation parameters simultaneously. Strong deviations from spheroidal shapes including reflection asymmetric ones are found. The influence of cluster deformation on the separation energies and ionization potentials and on the splitting of the photo - resonance are compared with the available experimental data. The N-dependence of the cluster shape and its relation to the N- and Z-dependences of the nuclear shape is discussed.