1. Physics Division, Lawrence Livermore National Laboratory, Livermore, California 94550, USA
2. College of Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
3. Chemistry Department, Brown University, Providence, Rhode Island 02912, USA
4. School of Engineering, Brown University, Providence, Rhode Island 02912, USA
5. Applications, Simulations and Quality Division, Lawrence Livermore National Laboratory, Livermore, California 94550, USA
6. Materials Science Division, Lawrence Livermore National Laboratory, Livermore, California 94550, USA