1. Department of Chemistry, University of Bristol, Cantock’s Close 1 , Bristol BS8 1TS, England, United Kingdom
2. Institute of Solid State Physics, University of Latvia 2 , 8 Kengaraga Street, LV1063 Riga, Latvia
3. Université de Lorraine - Nancy, CNRS, Laboratoire de Physique et Chimie Théoriques 3 , UMR 7019, Vandoeuvre-les-Nancy, France
4. Accademia delle Scienze di Torino 4 , Via Accademia delle Scienze, 6, 10123 Torino, Italy