1. Dipartimento Di Scienze Chimiche e Geologiche; Università di Modena e Reggio-Emilia; via G. Campi 103 Modena I-41125 Italy
2. Institut de Recherche de Chimie Paris, CNRS Chimie ParisTech; 11 Rue P. et M. Curie F-75005 Paris France
3. Gaussian Inc.; 340 Quinnipiac Str., Bldg. 40 Wallingford Connecticut 06492
4. Chemistry and Chemical Biology; University of California; Merced California 95343
5. Institut Universitaire de France; 103 Boulevard Saint Michel Paris F-75005 France