1. Department of Chemistry, University of Basel, Mattenstrasse 24a, BPR 1096, CH-4002 Basel, Switzerland
2. Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056 Basel, Switzerland
3. Department of Pharmacy, University of Copenhagen, DK-2100 Copenhagen, Denmark
4. Department of Physical Chemistry 1, Lund University, SE-221 00 Lund, Sweden