1. College of Physics and Electronics, Shandong Normal University, Jinan 250014, China, State Key Laboratory of Precision Spectroscopy and Department of Physics, Institute of Theoretical and Computational Science, East China Normal University, Shanghai 200062, China, Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, and Department of Chemistry, New York University, New York, New York 10003