1. Department
of General Physics
and Spectroscopy, Faculty of Physics, Vilnius University, Saulėtekio al. 9, LT-10222 Vilnius, Lithuania
2. Department of Physics, Chemistry
and Pharmacy, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
3. Department of Theoretical Chemistry
and Biology, School of Biotechnology, Royal Institute of Technology, SE-10691 Stockholm, Sweden