DENSITY-FUNCTIONAL THEORY OF THE COLLECTIVE ELECTRONIC EXCITATIONS IN NANKN CLUSTERS

The collective electronic response of NanKn clusters has been studied for some model structures. In their low-temperature lowest-energy structure, those clusters have all the K atoms on the surface. The collective oscillation frequencies for clusters with the K atoms segregated to the surface are red-shifted with respect to the corresponding frequencies for isomers with a very similar underlying skeleton but with the Na atoms segregated to the surface. The collective frequency varies smoothly with respect to the degree of relative segregation. These results may be useful in the analysis of the collective response of large alloy clusters and microcrystals. (C) 1995 John Wiley & Sons, Inc.