1. Mulliken Center for Theoretical ChemistryUniversity of Bonn Beringstraße 4+6 D-53115 Bonn Germany
2. Department of ChemistryInstitute for Advanced Studies in Basic Sciences (IASBS) Zanjan Iran
3. Dpto. Física Aplicada, Facultad de CienciasUniversidad de Vigo Campus Lagoas-Marcosende s/n 36310 VIGO – Spain
4. École Normale Supérieure de LyonLaboratoire de Chimie 46 allée d'Italie 69364 Lyon cedex 07 France