1. Faculty of Science, Department of Chemistry, University of Kragujevac, Kragujevac, Serbia
2. Department of Chemistry and Pharmacy, Institute for Inorganic Chemistry, University of Erlangen-Nürnberg, Erlangen, Germany
3. Computer Chemistry Center, Department of Chemistry and Pharmacy, University of Erlangen-Nürnberg, Erlangen, Germany
4. Faculty of Sciences, Department of Physics, University of Novi Sad, Novi sad, Serbia