1. School of Chemistry, University of Edinburgh, Joseph Black Building, David Brewster Road, Edinburgh EH9 3FJ, Scotland, United Kingdom
2. International Centre for Quantum and Molecular Structures, College of Sciences, Shanghai University, 99 Shangda Road, Shanghai 200444, China
3. Scuola Normale Superiore, Piazza Cavalieri 7, 56126 Pisa, Italy
4. ISM-CNR, Istituto di Struttura della Materia, LD2 Unit, 34149 Trieste, Italy
5. CNR-IOM Laboratorio TASC, Trieste, Italy
6. ISA, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C, Denmark
7. Department of Chemistry, Washington State University, Pullman, Washington 99164-4630, USA