1. Fakultät Physik, Technische Universität Dortmund, D-44221 Dortmund, Germany
2. Faculté des Sciences et Techniques, Université de Tours, 37200 Tours, France
3. QUILL Center, The Queen’s University of Belfast, Belfast BT9 5AG, Northern Ireland, United Kingdom
4. Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37916, USA and Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, USA