1. Institute of Geotechnics, Slovak Academy of Sciences, Watsonova 45, SK-04353 Košice, Slovakia
2. Institute of Physical and Theoretical Chemistry, Technical University of Braunschweig, Hans-Sommer-Str. 10, D-38106 Braunschweig, Germany
3. Laboratory of Inorganic Chemistry, Swiss Federal Institute of Technology Zurich, Hönggerberg, CH-8093 Zurich, Switzerland