1. Department of Chemistry, University of Bucharest, B-dul Regina Elisabeta, nr. 4-12, 030018 Bucharest, Romania
2. National Institute for Laser, Plasma and Radiation Physics, RO 76900 Bucharest-Magurele, Romania
3. National Institute of Materials Physics, 405A Atomistilor Street, 077125 Magurele-Ilfov, Romania
4. Department of Chemistry and Biotechnology, Biocenter, SLU, Box 7015, SE-75007 Uppsala, Sweden