1. Center
for Nanochemistry, Beijing National Laboratory for Molecular Sciences
(BNLMS), State Key Laboratory for Structural Chemistry of Unstable
and Stable Species, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, People’s Republic of China
2. Stanford
Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo
Park, California 94025, United States