1. Frankfurt Institute for Advanced Studies (FIAS), Johann Wolfgang Goethe-Universität, Ruth-Moufang-Str. 1, D-60438 Frankfurt am Main, Germany, Max Planck Institute for Polymer Research, Ackermannweg 10, D-55128 Mainz, Germany, Institute for Computational Physics, Universität Stuttgart, Pfaffenwaldring 27, D-70569 Stuttgart, Germany, and Clemens-Schöpf Institute for Organic Chemistry and Biochemistry, TU Darmstadt, Petersenstr. 22, D-64287 Darmstadt, Germany