1. Department of Chemistry, University of Virginia, P.O. Box 400319, Charlottesville, Virginia 22904-4319
2. LADIR/Spectrochimie Moléculaire CNRS UMR 7075- Université Pierre et Marie Curie, case 49, 4 place Jussieu, 75252 Paris, France
3. Department of Applied Science, University of California, Davis, Livermore, California 94550; Chemistry and Materials Science Directorate, Lawrence Livermore National Laboratory, University of California, Livermore, California 94550; Glenn T. Seaborg Center, Lawrence Berkeley Laboratory, University of California, Berkeley, California 94720