1. Contribution from the Department of Chemical Engineering and Materials Science, University of California, Irvine, California 92697, Department of Chemistry, Korea Advanced Institute of Science and Technology, 373-1 Guseong-dong, Yuseong-gu, Daejeon 305-701, Korea, National Center for Electron Microscopy, Lawrence Berkeley National Lab, MS 72-150, 1 Cyclotron Road, Berkeley, California 94720, and Quantum Science Research Group, Hewlett-Packard Laboratories, MS 1123, 1501 Page Mill Road, Palo Alto,...