1. Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, CH-3012 Bern, Switzerland
2. Key Laboratory of Cluster Science of Ministry of Education, School of Chemistry, Beijing Institute of Technology, 100081 Beijing, China
3. Lehrstuhl für Theoretische Chemie, Ruhr-Universitat Bochum, 44780 Bochum, Germany
4. Institut de Química Computacional i Catàlisi and Departament de Química, Universitat de Girona, Facultat de Ciències, C/ M. Aurèlia Campmany 69, 17003 Girona, Spain