1. Laboratoire Structures, Propriétés
et Modélisation des Solides (SPMS), CNRS UMR 8580, École Centrale Paris, Grande Voie des Vignes,
F-92295 Châtenay-Malabry, France
2. Department of Physics, Chemistry
and Pharmacy, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark
3. Dipartimento di Chimica e Chimica
Industriale, Università di Pisa,
via Risorgimento 35, I-56126 Pisa, Italy