1. Institute of Physics, Nicolaus Copernicus University in Toruń, Grudziądzka 5, 87-100 Toruń, Poland
2. Department of Chemistry, Missouri University of Science and Technology, Rolla, Missouri 65409-0010, USA
3. Univ. Rennes, CNRS, IPR (Institut de Physique de Rennes)-UMR 6251, Rennes F-35000, France