1. Eduard-Zintl Institute for Inorganic and Physical Chemistry, TU Darmstadt, Darmstadt 64287, Germany
2. Department of Radiology, Medical Physics, Medical Center—University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
3. Department of Chemistry, University of California at Berkeley, Berkeley, California 94720-3220, United States
4. International Tomography Center, Siberian Branch of the Russian Academy of Science, Novosibirsk 630090, Russia
5. Novosibirsk State University, Novosibirsk 630090, Russia