The research project involved static and dynamic properties of small systems which are of great fundamental and practical importance for the understanding of the physics of microstructures (small metal particles, electronic states in confined geometries, etc.). Our study concentrated on properties of the electronic wave functions of such structures with emphasis on electronic correlations, electron-phonon interactions, electron interference effects and tunneling processes. Special attention was paid to experimentally accessible quantities. Part of the research dealt with properties of superconductors of complicated electronic and magnetic structures. (orig.)SIGLEAvailable from TIB Hannover: DtF QN1(23,14) / FIZ - Fachinformationszzentrum Ka...