1. Kenneth S. Pitzer Theory Center and Department of Chemistry, University of California, Berkeley, CA, USA
2. Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
3. Theoretical Physics and Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen, 47048 Duisburg, Germany
4. Center for Molecular Modeling (CMM), Ghent University, B-9052 Ghent, Belgium
5. Department of Chemistry, Queen's University, Kingston, Ontario K7L 3N6, Canada
6. Department of Chemistry, Beijing Normal University, Beijing 100875, China
7. Departments of Bioengineering and Chemical and Biomolecular Engineering, University of California, Berkeley, CA, USA