1. Department of Chemistry and Chemical BiologyUniversity of New Mexico Albuquerque NM 87131 USA
2. Department of Dynamics at SurfacesMax Planck Institute for Biophysical Chemistry 37077 Göttingen Germany
3. Department of ChemistryUniversity of Washington Seattle WA 98195-1700 USA
4. Institute for Physical ChemistryUniversity of Göttingen 37077 Göttingen Germany