31. Theoretical Studies of Structural and Electronic Properties of Clusters

Clusters contain more than just some few atoms but not so many that they can be considered as being infinite. By varying their size, their properties can often be varied in a more or less controllable way. Often, however, the precise relation between size and property is largely unknown: the sizes of the systems are below the thermodynamic limit so that simple scaling laws do not apply. Theoretical studies of such systems can provide relevant information, although in many cases idealized systems have to be treated. The challenge of such calculations is the combination of the relatively large size of the systems together with an often unknown structure. In this presentation, different theoretical methods for circumventing these problems shall be discussed. They shall be illustrated through applications on various types of clusters. These include isolated metal clusters with one or two types of atoms, metal clusters deposited on a surface, nanostructured HAlO, semiconductor nanoparticles, and metallocarbohedrenes. Special emphasis is put on the construction of descriptors that can be used in identifying general trends.