1. Institut für Physikalische und Theoretische Chemie, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
2. Faculty of Mathematics and Physics, Charles University, Ke Karlovu 5, 121 16 Prague, Czech Republic
3. Department of Physics, University of Ottawa, Ottawa K1N 6N5, Canada
4. School of Electrical Engineering and Computer Science, University of Ottawa, Ottawa K1N 6N5, Canada
5. Center for Nanosystems Chemistry (CNC), Universität Würzburg, Theodor-Boveri-Weg, 97074 Würzburg, Germany