1. Department
of Geological Sciences, Stanford University, Stanford, California 94305, United States
2. Stanford
Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
3. Department
of Chemistry, Stanford University, Stanford, California 94305, United States
4. Geophysical Laboratory, Carnegie Institution of Washington, Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, United States