Stable structures of Al micro-clusters and their characteristics for electric charging

Ab initio theoretical calculations have been performed to obtain the stable structures for clusters consisting of a small number of Al atoms. Geometry optimization has revealed that there exists a stable planar structure for Al, clusters. The electron density distributions in the planar structures w ere examined for the electrically neutral, negative, and positive condition s of the Al clusters. Charge population maps suggested that the outer Al at oms of the cluster play a major role in the storage of extra electrons. In addition to the planar structure, nonplanar structures have been obtained f or Al clusters. However, the configuration of these structures is much diff erent from that of Al crystals. (C) 2000 Elsevier Science B.V. All rights r eserved.