1 \chapter*{Acknowledgment}
2 \addcontentsline{toc}{chapter}{Acknowledgment}
4 %First of all, I would like to thank Prof. Dr. Bernd Stritzker and Prof. Dr. Kai Nordlund for accepting me as a PhD student at their chairs at the University of Augsburg and Helsinki.
5 %Although Mr. Stritzker is doing experimental physics in Augsburg he gave me the opportunity to do this more or less theoretical work.
6 %During my stays in Finland Mr. Nordlund \ldots
12 \item Prof. B. Stritzker (accomodation at EP \RM{4})
13 \item Ralf Utermann (EDV)
18 \item Prof. K. Nordlund (MD)
23 \item Bayerische Forschungsstiftung (financial support)
28 \item Prof. J. Lindner (SiC)
29 \item Prof. G. Schmidt (DFT + financial support)
30 \item Dr. E. Rauls (DFT + SiC)
31 \item Dr. S. Sanna (VASP)