STRUCTURE AND ENERGETICS OF NAN-XLIX (N LESS-THAN-OR-EQUAL-TO 21) CLUSTERS

Hohenberg-Kohn-Sham density-functional theory is used to obtain the energy of valence electrons in a spherically averaged external ionic potential for Nan-xLix (n*21) clusters. By adding the ion-ion interaction and minimizing the total energy with respect to the ion positions, we then obtain the equilibrium geometry of the cluster. Strong similarities are found to exist between the characteristics of clusters with a common n and varying x. The substitution of Na atoms by Li atoms is a favorable reaction and appears to justify the Li enrichment observed in the experiments. The importance of low-lying metastable geometries for the interpretation of the abundance spectrum is stressed. © 1990 The American Physical Society.