1. Center for Free Electron Laser Science, Max Planck Institute for the Structure and Dynamics of Matter, Hamburg 22761, Germany
2. Nano-Bio Spectroscopy Group and European Spectroscopy Facility (ETSF), Universidad del País Vasco CFM CSIC-UPV/EHU-MPC & DIPC, 20018 Donostia-San Sebastián, Spain
3. Center for Computational Quantum Physics, Simons Foundation Flatiron Institute, New York 10010, New York, United States
4. Department of Materials, Imperial College London, London SW7 2AZ, U.K.
5. The Thomas Young Centre for Theory and Simulation of Materials, London SW7 2AZ, U.K.