1. Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, United States
2. Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126 Pisa, Italy
3. CSGI, Istituto Nazionale di Fisica Nucleare (INFN) Sezione di Pisa, Largo Bruno Pontecorvo 3, 56127 Pisa, Italy
4. Department of Chemistry and Biochemistry, Loyola University Chicago, Chicago, Illinois 60660, United States
5. Department of Chemistry & Biochemistry, Calvin University, Grand Rapids, Michigan 49546, United States
6. Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824, United States