1. Center for Polymers and Organic Solids University of California Santa Barbara CA 93106 USA
2. School of Chemistry and Environment Beihang University Beijing 100191 P. R. China
3. Tohoku University WPI‐AIMR and CNSI Joint Center University of California Santa Barbara CA 93106 USA
4. National Center for Nanoscience and Technology Beijing 100190 P. R. China
5. Department of Chemistry and Biochemistry California State University Northridge Northridge CA 91330 USA
6. Beijing Computational Science Research Center Beijing 10084 P. R. China