1. Institut für Organische Chemie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Henkestrasse 42, 91054 Erlangen, Germany, Center for Computational Quantum Chemistry, Computational Chemistry Annex, University of Georgia, 1004 Cedar Street, Athens, Georgia, 30602-2525, and Computational Center for Molecular Structure and Design, Department of Chemistry, University of Georgia, 1004 Cedar Street, Athens, Georgia, 30602-2525