1. Department of Chemistry, University of Oslo, P.O. Box 1033, Blindern, NO-0315 Oslo, Norway
2. Department of Biomaterials, Institute of Clinical Dentistry, University of Oslo, P.O. Box 1109, Blindern, NO-0317 Oslo, Norway
3. Department of Biosciences, University of Oslo, P.O. Box 1066, Blindern, NO-0316 Oslo, Norway
4. Department of Science and Environment, Roskilde University, 4000 Roskilde, Denmark
5. Hylleraas Centre for Quantum Molecular Sciences, University of Oslo, NO-0315 Oslo, Norway