1. Center for Nonlinear Systems, Kaunas University of Technology, Studentu 50-147, Kaunas LT-51368, Lithuania
2. Department of Physics, Faculty of Mathematics and Natural Sciences, Kaunas University of Technology, LT-51368 Kaunas, Lithuania
3. Department of Theoretical Chemistry and Biology, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, S-106 91 Stockholm, Sweden