1. Laboratoire de biomathématiques, Faculté de pharmacie, Université Paris Descartes, 75006 Paris, France, Institute of Solid State Physics, University of Latvia−Kengaraga 8, 1063 Riga, Latvia, L.U.R.E., Bat 209D, Université Paris XI, 91405 Orsay, France, and Laboratory of Bioinorganic Coordination Chemistry, University of Crete, Voutes Campus, 71003 Heraklion, Crete, Greece