1. Fritz Haber Institute of the Max-Planck-Society, Berlin 14195, Germany
2. Max-Planck-Institute for Chemical Energy Conversion, Mülheim an der Ruhr 45470, Germany
3. Istituto Officina dei Materiali, Consiglio Nazionale delle Ricerche, CNR-IOM, Trieste 34136, Italy
4. Theoretical Division, Los Alamos National Lab, Los Alamos, New Mexico 87545, United States
5. MAX IV Laboratory, Lund University, Lund 22484, Sweden