Quantum-chemical study of properties of mesoscopic germanium particles

In this study we investigate tetrahedral germanium clusters of n-shells containing a few hundreds of atoms by quantum-chemical methods and discussed: - The geometrical and electronic structures of these clusters. - Localization grade of the interactions. - Convergence of clusters properties to coincident values of bulk (middle value of binding energy per atom, middle value of coordination number and shortest pair distance between two near-neighboring atoms. Our quantum studies show that the cohesion of mesoscopic germanium particles results mainly from local pair interactions between nearest-neighboring atoms. The many-particle-interactions play only a slight role. Therefore, we suggest in case of germanium to search for suitable analytical pair potential-functions. And these can mainly simplify the dynamic studies. (author)