1. Beckman Institute, California Institute of Technology, Pasadena, California 91125, United States
2. Department of Chemistry and Chemical Biology, Cornell University, Baker Laboratory, Ithaca, New York 14853, United States
3. Instituto de Biología Molecular y Celular de Rosario, (IBR-CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531 (S2002LRK), Rosario, Argentina
4. EPSRC National UK EPR Facility and Service, Photon Science Institute, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K.
5. Theoretical Chemistry Section, Chemistry Group, Bhabha Atomic Research Centre, Mumbai-400 085, India
6. Institute for Physical and Theoretical Chemistry, University of Bonn, Wegelerstrasse 12, Bonn-53115, Germany
7. Max-Planck-Institut für Bioanorganische Chemie, Stiftstrasse 34-36, D-45470 Mülheim an der Ruhr, Germany