QUASICLASSICAL TRAJECTORY STUDY OF VIBRATIONAL PREDISSOCIATION OF VANDERWAALS MOLECULES - COLLINEAR HE...I2(B3PI)

Vibrational predissociation of the van der Waals molecule He⋯I 2(B 3Π) has been investigated using quasiclassical trajectories. The study was restricted to collinear motion to allow comparisons with the quantum mechanical calculations of Beswick and Jortner [J. Chem. Phys. 68, 2277 (1978); 69, 512 (1978)]. The unimolecular dissociation of He⋯I2(B 3Π) confined to a single adiabatic electronic potential-energy surface was studied as a function of the initial I2 vibrational quantum state, where a zeroth-order approximation of the separation of the I-I and He-I2 oscillators was made for the purpose of assigning initial states. The computed trajectory results show that the unimolecular decay as a function of time obeys the exponential decay law quite well. The computed decay rates are in accord with the quantum mechanical values and with experimental measurements. © 1979 American Institute of Physics.