1. Department of Materials Science
2. University of Milano-Bicocca
3. I-20125 Milano
4. Italy
5. Department of Chemistry and Centre for Scientific Computing
6. University of Warwick
7. Coventry CV4 7AL
8. UK
9. Universität Göttingen
10. Institut für Physikalische Chemie
11. Theoretische Chemie
12. 37077 Göttingen
13. Germany