1. Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
2. Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, California 94720, USA
3. Department of Physics, University of California, Davis, California 95616, USA
4. Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, USA
5. Chemical Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
6. Department of Inorganic Chemistry, Fritz Haber Institute of the Max Planck Society, 14195 Berlin, Germany