1. J. Higgins, C. Callegari, J. Reho, K. K. Lehmann, G. Scoles, Department of Chemistry, Princeton University, Princeton, NJ 08544, USA.
2. F. Stienkemeier, Fakulät für Physik, Universität Bielefeld, D-33615, Bielefeld, Germany.
3. W. E. Ernst, Department of Physics, Pennsylvania State University, University Park, PA 16802, USA.
4. M. Gutowski, Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA 99352, USA, and Department of Chemistry, University of Gdańsk, 80-952 Gdańsk, Poland.