ABSTRACT
The science of clusters as an intermediate territory between the well-established lands of atoms or molecules and the extended solids has emerged as an important area of research [1,2] not only from the point of view of fundamental understanding but also technological advancements in diverse areas of catalysis, materials science, nanotechnology, electronics, and so on. Of particular importance and interest is the fact that the properties in this state of matter show nonmonotonic size dependence which along with their approach to the bulk behavior with growth in size is more challenging to the researchers. The belief “There is plenty of room in the middle” has been strengthened through the emergence of new theoretical as well as experimental tools to investigate this state of matter. Understanding the properties of these small systems requires new theoretical tools since they may be too large to be amenable to direct electronic structure-based ab initio study but too small for the use of tools commonly used for the meso or macroscopic length scales. While isolated clusters themselves are
6.1 Introduction .................................................................................................. 103 6.2 Density Functional Theory ........................................................................... 105 6.3 Electrostatic Interaction Scheme for Polarizability ...................................... 107 6.4 Density Functional Perturbation Theory for Polarizability: A Coarse-Grained Approach ........................................................................ 108 6.5 DFT-Based Investigation of Polarizability of Metal Clusters ...................... 113 6.6 Concluding Remarks .................................................................................... 115 Acknowledgments .................................................................................................. 115 References .............................................................................................................. 116
important in their own right, their aggregate forming the so-called cluster assembled materials has created a new dimension in the area of research dealing with the design of novel materials as well as other aspects in materials science and technology. The progress in the emerging area of nanomaterials and nanotechnology is in fact heavily dependent on the understanding of the science of clusters.
