1. Departments of Chemistry and
Physics, University of California, Berkeley,
California 94720, United States
2. Institut de Physique de Rennes,
UMR 6251 du CNRS, Université de Rennes 1, 263 Avenue du Général Leclerc, 35042 Rennes Cedex,
France
3. Chemical Sciences
Division, Lawrence Berkeley National Laboratory, 1 Cyclotron
Road, Berkeley, California 94720, United States