QUANTUM-MECHANICAL STUDY OF THE I-2-NE VIBRATIONAL PREDISSOCIATION DYNAMICS - A 3-DIMENSIONAL TIME-DEPENDENT SELF-CONSISTENT-FIELD APPROACH

A three-dimensional time-dependent self-consistent-held (TDSCF) approa ch is proposed to study the vibrational predissociation of the I-2(B)- Ne van der Waals (vdW) complex. Jacobian coordinates are used within t he assumption of zero-total angular momentum. In the method the total wave function is factorized such that the bending mode of the system i s explicitly separated, while the coupling between the remaining two d egrees of freedom is treated exactly. The decay dynamics of several re sonances corresponding to different initial vibrational states of It i s investigated through long-time wave packet propagations. Calculated resonance Lifetimes are compared to experimental data and found to be in quantitative agreement with them. The results show that predissocia tion of the complex is mainly governed by the coupling between the I-2 and the vdW stretching vibrations, whereas the bending mode has a rat her weak effect on the dynamics. The good quality of the TDSCF descrip tion of this long-time dynamical process is due to the adaptation of t he decoupling approximations applied in the method to the physical sit uation of the system. The validity of the approach is discussed in the light of the results. (C) 1996 American Institute of Physics.