1. IFW Dresden, P.O. Box 270116, D-01171 Dresden,Germany
2. Institut für Festkörperphysik, TU Dresden, Mommsenstrasse 13, D-01069 Dresden, Germany
3. Interdisciplinary Laboratory for Computational Science (LISC), FBK-CMM and University of Trento, via Sommarive 18, I-38123 Trento, Italy
4. Department of Physics, University of Trento, Via Sommarive 14, I-38100, Trento, Italy
5. Department of Physics, Budapest University of Technology and Economics, Budafoki út 8, 1111 Budapest, Hungary
6. Institute for Research in Fundamental Sciences (IPM), P.O. Box 19395-5531, Tehran, Iran
7. Helmholtz-Zentrum Berlin für Materialien und Energie, Elektronenspeicherring BESSY II, Albert-Einstein-Strasse 15, D-12489 Berlin, Germany
8. Faculty of Physics, University of Vienna, Strudlhofgasse 4, 1090 Wien, Austria
9. Institut für Physik, Universität Augsburg, D-86135 Augsburg, Germany
10. Department of Physics, University of Camerino, via Madonna delle Carceri 9, 62032 Camerino, Italy
11. Department of Physics and Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139-4307