[1] Sincrotrone Trieste, I-34012 Trieste, Italy
[2] CNR, ISMN, Sez Roma 1, I-00185 Rome, Italy
[3] INFM, TASC, I-34012 Trieste, Italy
[4] CNR, IMIP, Area Ric Roma, I-00016 Monterotondo, Italy
[5] Univ Roma La Sapienza, Dipartimento Chim, I-00185 Rome, Italy
[6] Isfahan Univ Technol, Dept Chem, Esfahan 84154, Iran
[7] Abdus Salam Int Ctr Theoret Phys, I-34014 Trieste, Italy