1. Institut für Organische Chemie der Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany, Department of Chemistry, University of Idaho, Box 442343, Moscow, Idaho 83844-2343, Department of Chemistry and Supercomputer Institute, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455-0431, and the Departments of Chemistry, Transylvania University, Lexington, Kentucky 40508, and University of Washington, Box 351700, Seattle, Washington 98195-1700