1. Department of Chemistry, University of Warwick, Coventry CV4 7AL, United Kingdom
2. Max-Planck-Institut für Eisenforschung GmbH, 40237 Düsseldorf, Germany
3. School of Chemical Sciences, Dublin City University, Glasnevin, Dublin 9, Ireland
4. Institute for Physical Chemistry, University of Göttingen, 37077 Göttingen, Germany
5. Current affiliation: Interdisciplinary Center for Scientific Computing, University of Heidelberg, 69120 Heidelberg, Germany
6. Institute of Solid State Physics, Graz University of Technology, NAWI Graz, 8010 Graz, Austria
7. Physics, Faculty of Science and Engineering, Åbo Akademi, FI-20500 Turku, Finland
8. Laboratoire de Physique et Chimie Théoriques, CNRS UMR 7019, Institut Jean Barriol, Université de Lorraine, BP 239, 54506 Vandoeuvre-lès-Nancy, France
9. Physics and Materials Science Research Unit, University of Luxembourg, L-1511 Luxembourg, Luxembourg