1. Department of Chemistry, University of Oslo, P. O. Box 1033 Blindern, N-0315 Oslo, Norway
2. Centre for Materials Science and Nanotechnology, University of Oslo, P.O. Box 1126 Blindern, N-0316 Oslo, Norway
3. Department of Chemistry, NIS and INSTM Reference Centre, Università di Torino, Via G. Quarello 15/A, I-10135, and Via P. Giuria 7, I-10125, Turin, Italy
4. University School for Advanced Studies, IUSS Pavia, Palazzo del Broletto, Piazza della Vittoria 15, I-27100, Pavia, Italy
5. Hylleraas Centre for Quantum Molecular Sciences, Department of Chemistry, University of Oslo, N-0315 Oslo, Norway