1. Department of Chemistry, NIS Centre and INSTM, University of Turin, Via G. Quarello 15/A, Turin, I-10135, Italy
2. Institut Laue-Langevin (ILL), 71 Avenue des Martyrs, 38042 Grenoble, France
3. Chimet SpA–Catalyst Division, Via di Pescaiola 74, Viciomaggio Arezzo, I-52041, Italy