1. Department of Physical and Quantum Chemistry, Faculty of Chemistry; Wrocław University of Technology; Wyb. Wyspiańskiego 27 PL-50370 Wrocław Poland
2. Division of Theoretical Chemistry and Biology; School of Biotechnology, Royal Institute of Technology; SE-10691 Stockholm Sweden
3. Lehrstuhl fuer Theoretische Chemie; Ruhr-Universität Bochum, Universitätsstrasse 150; D-44780 Bochum Germany