TRIAXIALLY DEFORMED SODIUM CLUSTERS IN A SELF-CONSISTENT MICROSCOPIC DESCRIPTION

We have performed self-consistent Kohn-Sham calculations for the triaxially deformed sodium clusters Na12 and Na14. We use the jellium approach and compute the properties of the valence electrons with an exchange-correlation energy functional in the local density approximation. In both clusters a pronounced shape isomerism is obtained. We find a well-developed triaxial ground-state deformation for Na12 which produces a triple-peaked dipole surface plasmon, as experimentally observed, whereas Na14 maintains axial symmetry but with two almost degenerate oblate and prolate minima.