1. Institute of Condensed Matter and Nanosciences (IMCN), European Theoretical Spectroscopy Facility (ETSF), Université Catholique de Louvain, Place Croix du Sud 1 (PCPM-Boltzmann), 1348 Louvain-la-Neuve, Belgium
2. CEA, INAC, SPSMS, 17 rue des Martyrs, 38054 Grenoble Cedex 9, France
3. CEA, LETI, MINATEC, F38054 Grenoble, France
4. CEA, INAC, SP2M, L_sim, 17 rue des Martyrs, 38054 Grenoble Cedex 9, France
5. Departamento Electrónica y Tecnología de Computadores, Facultad de Ciencias, & CITIC, Universidad de Granada, E-18071 Granada, Spain
6. Institute for Materials Science, TU Dresden, D-01062 Dresden, Germany
7. CIN2 (CSIC-ICN), Campus de la U.A.B., 08193 Bellaterra, Barcelona, Spain