1. Department of Physics and Astronomy, Uppsala University, 751 20 Uppsala, Sweden
2. Department of Chemistry - Ångström, Uppsala University, 751 20 Uppsala, Sweden
3. MAX IV Laboratory, Lund University, 225 94 Lund, Sweden
4. Institute for Applied Materials (IAM), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany