3-DIMENSIONAL WAVE-PACKET STUDIES OF OZONE PHOTODISSOCIATION IN THE HARTLEY BAND - CONVERGED AUTOCORRELATION FUNCTIONS AND ABSORPTION-SPECTRA

We report fully converged autocorrelation functions governing the photodissociation of ozone in the Hartley band, by an exact solution of the time-dependent Schrodinger equation. A local-mode representation employing hyperspherical coordinates has been used for describing the dynamics. Two different potential energy surfaces (PESs) have been employed in the present investigation, and the results showed sensitivity to the choice of the PES. Our converged calculation for J=0 on the Sheppard-Walker PES near quantitatively reproduced the characteristic recurrence features in the autocorrelation function obtained by Johnson and Kinsey from the experimental spectrum of Freeman et al. This is in contrast to previously reported three-dimensional calculations which showed a factor of 10 higher recurrence intensities compared to the experimentally derived one. The absorption spectrum, obtained as the Fourier transform of the autocorrelation function, is in excellent agreement with the experimental spectrum and exhibits the unique features seen on top of the experimental spectrum, which has caused considerable theoretical interest over recent years. Calculations on the Yamashita-Morokuma surface showed a factor of 5 higher intensity for the recurrence features, in agreement with existing three-dimensional calculations. The effect of J on the autocorrelation function has also been investigated by carrying out a calculation for J=10 and invoking a planar approximation. The J effect became noticeable only at a later time (t>150 fs) of the dissociation process and its effect on the absorption spectrum was found to be only marginal.