1. Institut für
Anorganische und Analytische Chemie, Friedrich-Schiller-Universität Jena, Humboldtstr. 8, 07743 Jena, Germany
2. Institute of Applied Physics, Academy of Sciences of Moldova, Academiei str.5, MD-2028, Chisinau, Moldova
3. Institute of Physics, Jagiellonian University, Łojasiewicza 11, 30-348 Krakow, Poland
4. Eduard-Zintl-Institute
of Inorganic and Physical Chemistry, Darmstadt University of Technology, Alarich-Weiss-Str. 4, 64287 Darmstadt, Germany