1. Department of Chemistry and Physics of Materials, Paris-Lodron University Salzburg, Jakob-Haringer-Straße 2a, Salzburg A-5020, Austria
2. Department of Physical Chemistry, University of Chemistry and Technology, Technická 5, Prague 166 28, Czech Republic
3. Department of Ion Physics and Applied Physics, University of Innsbruck, Technikerstraße 25, Innsbruck A-6020, Austria