[1] Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA
[2] Univ Cambridge, Dept Chem Engn & Biotechnol, Cambridge, England
[3] Duke Univ, Dept Chem, Durham, NC 27708 USA
[4] Univ Calif Berkeley, Coll Chem, Berkeley, CA 94720 USA
[5] Helmholtz Inst Mainz, D-55099 Mainz, Germany
[6] Rhein Westfal TH Aachen, Aachen, Germany
[7] Jagiellonian Univ, Inst Phys, PL-30348 Krakow, Poland
[8] Lawrence Berkeley Natl Lab, Nucl Sci Div, Berkeley, CA 94720 USA
[9] Johannes Gutenberg Univ Mainz, Helmholtz Inst Mainz, Mainz, Germany