1. University of Bern Department of Chemistry & Biochemistry Freiestr. 3 3012 Bern Switzerland
2. University of Nottingham School of Chemistry University Park Nottingham NG7 2RD UK
3. Max-Planck Institut für Kohlenforschung Department of Molecular Theory and Spectroscopy Kaiser-Wilhelm-Platz 1 45470 Mülheim an der Ruhr Germany