Unimolecular dissociation dynamics of highly vibrationally excited DCO((X)over-tilde(2)A') .2. Calculation of resonance energies and widths and comparison with high-resolution spectroscopic data

We present a theoretical study of the unimolecular dissociation of DCO in the electronic ground state, (X) over bar (1)A', using a new ab initio potential energy surface. Altogether we have analyzed about 140 resonances up to an energy of approximate to 1.4 eV above the D+CO threshold, corresponding to the ninth overtone in the CO stretching mode (v(2)=9) The agreement of the resonance positions and widths with recent stimulated emission pumping measurements of Stock et al. [J. Chem. Phys. 106, 5333 (1997), the preceding article] is pleasing. The root-mean-square deviation from the experimental energies is only 16 cm(-1) over a range of about 16 500 cm(-1) and all trends of the resonance widths observed in the experiment are satisfactorily reproduced by the calculations. A strong 1:1:2 stretch-stretch-bend resonance prohibits a unique assignment for the majority of vibrational states. (C) 1997 American Institute of Physics.