1. Institute of Inorganic and Analytical Chemistry, BCH, and the Institute of Crystallography, BSP, University of Lausanne, CH-1015-Lausanne, Switzerland, Department of Inorganic, Analytical and Applied Chemistry, Sciences II, University of Geneva, CH-1211 Geneva-4, Switzerland, and Pharma Division, Hoffmann-La Roche, CH-4070 Basle, Switzerland