1. Centre
for Theoretical and Computational Chemistry (CTCC), Department of
Chemistry, University of Oslo, P.O. Box 1033, Blindern, NO-0315 Oslo, Norway
2. Institut
des Sciences
Chimiques de Rennes, École Nationale Supérieure de Chimie
de Rennes, CNRS, UMR 6226, 11 Allée
de Beaulieu, CS 50837, 35708 Rennes Cedex 7, France