1. Department of Applied Physics, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, NL-9747AG Groningen, The Netherlands
2. Institute of Molecules and Materials, Radboud University of Nijmegen, NL-6525ED Nijmegen, The Netherlands
3. Department of Physics, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-8656, Japan
4. CREST, JST, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan
5. Institute for Advanced Simulation, Jülich Supercomputing Centre, Research Centre Jülich, D-52425 Jülich, Germany