1. ICFO − Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain
2. LENS and CNR-INO, Via Nello Carrara 1, 50019 Sesto Fiorentino (FI), Italy
3. Dipartimento di Fisica ed Astronomia, Università di Firenze, Via Sansone 1, 50019 Sesto Fiorentino (FI), Italy
4. ICMAB-CSIC − Institut de Ciència de Materials de Barcelona, Campus de la UAB, 08193 Bellaterra (Barcelona), Spain
5. Physikalisches Institut, Westfälische Wilhelms, Universität Münster, Heisenbergstrasse 11, 48149 Münster, Germany
6. Institute for Chemistry of OrganoMetallic Compounds (ICCOM − CNR), Via Madonna del Piano, 50019 Sesto Fiorentino (FI), Italy
7. QSTAR, Largo Fermi 2, 50125 Firenze, Italy
8. ICREA − Institució Catalana de Recerça i Estudis Avancats, 08010 Barcelona, Spain