1. Department of Chemistry; Wayne State University; Detroit Michigan 48202
2. Laboratoire De Chimie Théorique, UPMC Univ. Paris 06; UMR 7617 Paris F-75005 France
3. Institut Du Calcul Et De La Simulation, UPMC Univ. Paris 06; Paris F-75005 France
4. Institut Fur Physikalische Chemie, Universitat Mainz; Duesbergweg 10-14 Mainz D-55128 Germany