1. Department of Chemistry, University of California, Berkeley, California 94720, United States
2. Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
3. Kenneth S. Pitzer Theory Center, University of California, Berkeley, California 94720, United States
4. Kavli Energy NanoScience Institute, Berkeley, California 94720, United States
5. Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
6. Departments of Bioengineering and Chemical and Biomolecular Engineering, University of California, Berkeley, California 94720, United States
7. Department of Materials Science and Engineering, University of California, Berkeley, California 94720, United States