1. Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46,
02-668 Warszawa, Poland
2. Physikalisch-Chemisches Institut, Justus-Liebig-Universität Giessen, Heinrich-Buff-Ring
58, D-35392 Giessen, Germany
3. Department of Chemistry, University of Virginia, McCormick Road,
Charlottesville, Virginia 22904, United States
4. Department of Physics, The Ohio State University, 191 West
Woodruff Avenue, Columbus, Ohio 43210-1106, United States