1. Departament de Química Física and IQTCUB, Facultat de Química, Universitat de Barcelona, Martí i Franquès 1, 08028 Barcelona, Spain
2. Department of Chemistry, Imperial College London, South Kensington Campus, SW7 2AZ London, U.K.
3. Department of Physics
4. Carlson School of Chemistry and Biochemistry, Clark University, 950 Main Street, Worcester, Massachusetts 01610
5. Helmholtz-Zentrum Berlin für Materialien und Energie, 14109 Berlin, Germany