DEFORMATIONS OF QUASI-2-DIMENSIONAL ELECTRON-GAS CLUSTERS

Shell effects and Jahn-Teller deformations of quasi-two-dimensional je llium droplets are studied. Utilizing the ultimate jellium assumption, previously successfully used for three-dimensional systems, we calcul ate unrestricted shape relaxations and binding energies of the ground- state and the lowest isomers, using the methods of density-functional theory in the local spin-density approximation. Strong variations with particle number are found in the shape of the droplets. In particular , for certain magic electron numbers the shapes show triangular or cir cular symmetry, while for other electron numbers, more complicated sym metries are found. We finally show that from a more simple ''billiard' ' model one gains a qualitative understanding of the mechanisms behind the shape deformations. [S0163-1829(98)04935-2].