Affiliation: | 1. University of Helsinki, Department of Chemistry, University of Helsinki, P.O. Box 55, FI-00014 Helsinki, Finland;2. University of Tartu, Institute of Physics, Department of Materials Science, Ravila 14c, EE-50411 Tartu, Estonia;3. National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, EE-12618 Tallinn, Estonia |