ASSIGNMENT OF THE TORSIONAL STRUCTURE OF THE 0(0)0-BAND OF THE ELECTRONIC-TRANSITION A1G-]B2U IN VAN-DER-WAALS CLUSTERS OF TYPE-C6H6-X (X=N2, CO2, CO)

Using a model potential of hindered rotation of a linear molecule desc ribed by lambdacos2theta+mu(1-cos6phi), the torsional structure of the 0(0/0) band of the electronic transition A1g-->B2u in van der Waals c lusters Of type C6H6-X (X = N2, CO2, CO) was calculated. The assignmen t was made taking into account allowed transitions in accordance with the appropriate groups G3/12, G5/24. Satisfactory agreement was obtain ed for C6H6-N2 provided changes of the torsional barrier values were s mall between the lower (lambda,mu) and the upper (lambda',mu') states of the transition. Discrepancies in the experimental and calculated po sitions of the bands in the 0(0/0) transitions Of C6H6-CO2 and C6H6-CO are discussed.