1. Department
of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
2. School
of Materials Science and Engineering, Sun Yat-Sen University, No.
135, Xingang Xi Road, Guangzhou 510275, P. R. China
3. Faculty
of Applied Physics and Mathematics, Gdansk University of Technology, Narutowicza 11/12, 80-233 Gdansk, Poland
4. Condensed
Matter Physics and Materials Science Departments, Brookhaven National Laboratory, Upton, New York 11973, United States