[1] Vilnius Univ, Fac Phys, Dept Theoret Phys, Sauletekio Ave 9-3, LT-10222 Vilnius, Lithuania
[2] Ctr Phys Sci & Technol, Sauletekio Ave 3, LT-10257 Vilnius, Lithuania
[3] Lund Univ, Dept Chem Phys, POB 124, S-22100 Lund, Sweden
[4] Univ Oxford, Chem Res Lab, Dept Chem, Mansfield Rd, Oxford OX1 3TA, England
[5] Charles Univ Prague, Fac Math & Phys, Ke Karlovu 3, CR-12116 Prague, Czech Republic