1. Contribution from the Departments of Chemistry and Physics, Flinders University of South Australia, G.P.O. Box 2100, Adelaide, SA 5001, Australia, Division of Information Technology, CSIRO, Swanston Street, Carlton, Victoria 3053, Australia, Institute für Physikalische and Theoretische Chemie, Technische Universität, D-38106, Braunschweig, Germany, Institute of Advanced Studies, R. S. Phys. S. E., Australian National University, Canberra, ACT 0200, Australia, and Division of Chemicals and Polymers, CSIRO...