1. Department
of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599-3290, United States
2. Institute
of Physics, University of Szczecin, Wielkopolska 15, 70451 Szczecin, Poland
3. Institute
of Physical Chemistry, Bulgarian Academy of Sciences, Sofia 1113, Bulgaria
4. Institut
für Physik, Johannes Gutenberg Universität Mainz, Staudinger Weg 7, D-55099 Mainz, Germany
5. Department
of Chemistry, University of Virginia, Charlottesville, Virginia 22901, United States