1. Department of Physics, Chemistry and Biology, Linköping University, SE-581 83, Linköping, Sweden, Escola de Química, Universidade Federal do Rio de Janeiro, Caixa Postal 68542, CEP 21949-900, Rio de Janeiro, RJ, Brazil, Department of Applied Mathematics, Australian National University, Canberra, Australia, Department of Chemical Engineering, University of California, Berkeley, California 94720-1462, and Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720