1. Department of Chemistry and Department of Biology, Indiana University, Bloomington, Indiana 47405, Department of Materials Science and Technology and Department of Physics, University of Crete, 710 03 Heraklion, Crete, Greece, and Institute of Electronic Structure and Laser, Foundation for Research and Technology - Hellas, P.O. Box 1527, 711 10 Heraklion, Crete, Greece