1. Department of Chemistry, Willard H. Dow Laboratories, University of Michigan, Ann Arbor, Michigan 48109, United States
2. Phantom-g, CICECO-Aveiro Institute of Materials, Department of Physics, University of Aveiro Campus de Santiago, Aveiro 3810-193, Portugal
3. Centre de Biophysique Moléculaire CNRS UPR 4301, 45071 Orléans Cedex 2, France