1. University of Modena and Reggio Emilia & INSTM; Department of Chemical and Geological Sciences; via G. Campi 103 41125 Modena Italy
2. University of Florida; Department of Chemistry; Gainesville, FL, 32611-7200 USA
3. University of Modena and Reggio Emilia; Department of Physics, Informatics and Mathematics; via G. Campi 213/a 41125 Modena Italy