1. Institute of Molecular Physics, Polish Academy of Sciences, 60-179 Poznan (Poland)
2. Centre Hyperfrequences et Semiconducteurs, Universite de Lille I, 59655 Villeneuve d'Ascq (France)
3. Laboratoire de Chimie Theorique, Universite de Nancy I, 54506 Vandoeuvre les Nancy (France)
4. Institute of Chemistry, Military Technical Academy, 01-489 Warsaw (Poland)