The monograph is devoted to the relatively new and fast developing field of cluster physics. It is based on talks given at the Cluster Workshops, which were held in Pushchino in 1995 and 1996. The reports focus not only on the fundamental physical properties of clusters such as their geometric and electronic structure, as well as optical, thermal and magnetic properties, but also on a broad spectrum of their potential applications. These include nucleation and growth of small particles, fabrication of new materials with predefined properties (cluster-assembled and nanostructures). Some aspects of simulations and calculations of small particles and clusters are also discussed.We hope that our monograph will be of interest to a broad range of readers who will be able to sense the excitement of the talks.

Cluster physics is the foundation of the increasingly important field of nanotechnology. Clusters, ranging in size from a few to many millions of atoms, constitute a fascinating field of research in physics, chemistry and materials science. They are formed by most of the elements of the Periodic Table, and the types of bonding and the resultant clusters are equally as varied. This book introduces atomic clusters, ranging from weakly-bonded clusters of argon to strongly-bonded carbon clusters and metal nano-particles. It includes worked examples to enable lecturers and students to gauge their understanding and progress. Atomic and Molecular Clusters describes the experimental generation, detection and interrogation of clusters and theoretical approaches developed to aid understanding of their physical properties. It classifies clusters according to their bonding types and gives examples of present and possible future applications of clusters in electronic, optical and magnetic devices.

The book summarises contemporary knowledge about the theory of atomic and molecular clusters. New results are discussed on a high theoretical level. Access to this field of research is given by an explanation of the various subjects in introductory chapters.

Mergers are the mechanisms by which galaxy clusters are assembled through the hierarchical growth of smaller clusters and groups. Major cluster mergers are the most energetic events in the Universe since the Big Bang. Many of the observed properties of clusters depend on the physics of the merging process. These include substructure, shock, intra cluster plasma temperature and entropy structure, mixing of heavy elements within the intra cluster medium, acceleration of high-energy particles, formation of radio halos and the effects on the galaxy radio emission. This book reviews our current understanding of cluster merging from an observational and theoretical perspective, and is appropriate for both graduate students and researchers in the field.

Numerous experiments and calculations have shown that isolated metal clusters possess many interesting features, quite different from those known from surface and solid- state physics or from atomic and molecular physics. The technological exploitation of these new properties, e.g. in miniature electronic or mechanical components, requires the cluster to be brought into an environment such as an encapsulating matrix or a surface. Due to the interaction with the contact medium, the properties of the clusters may change or even disappear. Thus the physics of cluster-on-surface systems -- the main subject of this book -- is of fundamental importance. The book addresses a wide audience, from the newcomer to the expert. Starting from fundamental concepts of adsorbate-surface interactions, the modification of electronic properties through electron confinement, and concepts of cluster production, it elucidates the distinct properties of the new metallic nanostructures.

These issues represent a compendium of review papers covering almost every aspect of the physics of clusters and nanophase materials. Papers have been written by leading international experts in the field. The purpose of this compendium has been to illustrate, in more detail than is possible in a conference paper, the fundamental or underlying principles.

On Friday, February 20, 1980, I had the pleasure to be present at the inaugural lecture of my colleague Jan Reedijk, who had just been named at the Chair of Inorganic Chemistry of Leiden University. According to tradition, the ceremony took place in the impressive Hall of the old University Academy Building. In the course of his lecture, Jan mentioned a number of recent developments in chemistry which had struck him as particularly important or interesting. Among those was the synthesis of large metal cluster compounds, and, to my luck, he showed a slide ofthe molecular structure of [PtI9(C)b]4-. (To my luck, since at traditional Leiden University it is quite unusual to show slides at such ceremonies.) This constituted my first acquaintance with this exciting new class of materials. I became immediately fascinated by this molecule, partly because of the esthetic beauty of its fivefold symmetry, partly because as a physicist it struck me that it could be visualized as an "embryonically small" metal particle, embedded in a shell of CO ligands.