1. School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, U.K.
2. Division of Chemical Physics, Chemical Center, Lund University, Box 124, Lund SE-221 00, Sweden
3. Centre for Analysis and Synthesis, Department of Chemistry, Lund University, Box 124, Lund SE-22100, Sweden
4. Division of Synchrotron Radiation Research, Department of Physics, MAX IV Laboratory, Lund University, Box 118, Lund SE-22100, Sweden
5. Theoretical Chemistry Division, Chemical Center, Lund University, Box 124, Lund SE-221 00, Sweden