a
Institut de Chimie de Strasbourg (UMR 7177 CNRS/UdS), University of Strasbourg, 4 rue Blaise Pascal, F-67000 Strasbourg, France
E-mail: djukic@unistra.fr
;
Fax: (+33) 036885001
b
Mulliken Center for Theoretical Chemistry, University of Bonn, Beringstr. 4, D-53115 Bonn, Germany