NONADDITIVE INTERACTIONS AND THE RELATIVE STABILITY OF NEUTRAL AND ANIONIC SILVER CLUSTERS

We discuss the physical nature of nonadditivity in many-particle syste ms and the methods of calculations of nonadditive contributions to the interaction energy. For neutral clusters, a closed recurrence formula which expresses the energy of m-body interactions through the energie s of 2-, 3-, and (m - 1)-body ones is obtained. The general approach f or calculation of the nonadditive contribution in the interaction ener gy of charged systems is developed. The comparative calculation of ani onic and neutral silver clusters shows that the geometry of the most s table anionic clusters is established mainly by the additive forces. T he stability of neutral silver clusters is determined by the competiti on of attractive additive forces and repulsive nonadditive ones. (C) 1 995 John Wiley & Sons, Inc.