1. Theoretical Chemistry, Chemical Center, POB 124, S-221 00 Lund, Sweden, LRRS, UMR CNRS 5313, Universite de Bourgogne, F-21078 Dijon Cedex, France, PMMH, ESPCI, 10 rue Vauquelin, F-75231 Paris Cedex 05, France, and Physical Chemistry 1, Chemical Center, POB 124, S-221 00 Lund, Sweden