1. Laboratory of Computational Chemistry and Biochemistry and Laboratory for Biomolecular Modeling, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland, International School for Advanced Studies (SISSA/ISAS) and CNR-INFM-DEMOCRITOS, I-34014 Trieste, Italy, and Italian Institute of Technology, Italy