1. Department of Chemistry, University of California, Berkeley, California 94720, United States
2. Pfizer, Inc., BioTherapeutics Pharmaceutical Sciences, 700 Chesterfield Parkway West, Chesterfield, Missouri 63017, United States
3. Pfizer, Inc., Vaccines R&D, 10646 Science Center Drive, San Diego, California 92121, United States
4. Materials Sciences Division, Lawrence Berkeley National Laboratories, Berkeley, California 94720, United States