Faculty of Mathematics and Computer Science, University of Hagen, D-58084, Hagen, Germany. clemens@zvacek.de.|Faculty of Mathematics and Computer Science, University of Hagen, D-58084, Hagen, Germany. gerald.friedrichs@fernuni-hagen.de.|Institute of Biophysics and Physical Biochemistry, University of Regensburg, D-93040, Regensburg, Germany. leonhard.heizinger@ur.de.|Institute of Biophysics and Physical Biochemistry, University of Regensburg, D-93040, Regensburg, Germany. rainer.merkl@ur.de.