1. Max-Planck-Institut für Dynamik und Selbstorganisation, Bunsenstrasse 10, D-37073 Göttingen, Germany
2. Lawrence Berkeley National Laboratory, 1 Cyclotron Road 2-306, Berkeley, California 94720, United States
3. Wilhelm-Ostwald-Institute for Physical and Theoretical Chemistry, University Leipzig, Linnéstrasse 2, D-04103 Leipzig, Germany