DECOUPLING SURFACE-ANALYSIS OF CL+CL2 REACTION EMBEDDED IN AR52 CLUSTER

A model triatomic reaction Cl+Cl2-->Cl2+Cl embedded in an Ar52 van der Waals cluster is analyzed classical mechanically by a novel theoretic al method called ''decoupling surface analysis''. This method generate s new reactive and vibrational variables in which the kinetic coupling as well as the potential coupling are minimized. An analysis of local frequencies of the vibrational variables along the reaction coordinat e clarifies how the motions of ambient Ar atoms are coupled with the c entral Cl3 system. When the local frequencies are plotted as a functio n of the reaction coordinate, avoided crossings among these curves are observed. Mixing of Cl motion and Ar motion is clearly detected by th ese avoided crossings. The vibrational mode having a character of the symmetric stretch of Cl3 shows exclusively strong coupling with the re active motion. This mode, however, very weakly couples with the ambien t Ar motion. On the other hand, the bending and translation of Cl3 are strongly mixed with the motions of ambient Ar atoms and produce unsta ble modes, which play the most significant role in energy exchange bet ween the central reaction system and the ambient Ar atoms.