STABILITY OF NANPB (N-LESS-THAN-OR-EQUAL-TO-7) CLUSTERS - A FIRST-PRINCIPLES MOLECULAR-DYNAMICS STUDY

摘要

The structural and electronic properties of bimetallic clusters NanPb (n less than or equal to 7) are calculated by means of a first-principles molecular-dynamics simulated annealing, using the local-density approximation and the pseudopotential plane-wave method. We obtain that the observed exceptional abundance of Na6Pb in molecular beams is due to the combination of electronic and geometrical factors, which are absent in the case of n not equal 6 clusters. In particular, we find that adding another Na atom to Na6Pb is energetically less favorable than adding it to a pure Na cluster, in contrast to what we obtain for smaller NanPb clusters. [References: 48]