1. Dipartimento di Chimica, Università degli Studi di Perugia Via Elce di Sotto 8 06123-Perugia Italy
2. Institute of Atomic and Molecular Sciences Academia Sinica No.1, Roosevelt Road, Sec.4 Taipei, 10617 Taiwan
3. Dalian Institute of Chemical Physics Chinese Academy of Sciences 457 Zhongshan Road Dalian 116023 P.R. China