AB-INITIO STUDY OF THE PHOTODISSOCIATION OF HCO IN THE FIRST ABSORPTION-BAND - 3-DIMENSIONAL WAVE-PACKET CALCULATIONS INCLUDING THE (X)OVER-TILDE(2)A'-(A)OVER-TILDE(2)A'' RENNER-TELLER COUPLING

We present a comprehensive investigation of the Renner-Teller induced dissociation of <HCO((A)over tilde)> following excitation in the first absorption band <((A)over tilde (2)A ''<--(X)over tilde (2)A')>. The dynamics calculations are performed in the time-dependent picture by p ropagating two coupled wave packets including all three internal degre es of freedom. The corresponding potential energy surfaces have been g enerated from new electronic structure calculations, The quantities of interest are (i) the vibronic excitation energies in the <(A)over til de (2)A ''> state, (ii) the state-and K-dependent lifetimes of the rov ibronic states in the excited manifold, and (iii) the final vibrationa l-rotational state distributions of the fragment CO molecule. In all c ases very satisfactory agreement with recent experimental results obta ined from photofragment yield spectroscopy is achieved. (C) 1997 Ameri can Institute of Physics.