The role of rotation in the calculated ultraviolet photodissociation spectrum of ozone

Abstract

We present exact quantum calculations of the photodissociation of ozone in the Hartley band. These calculations rely on an hyperspherical description of the system, including rotation. A pseudospectral approach has been used for an efficient implementation of this scheme. The autocorrelation function has been directly computed by means of a Lanczos scheme, augmented by a complex absorbing potential. Using a single excited potential energy surface (D 1B2), calculations up to J=17 are reported. It is shown that in these conditions rotation has only marginal effects over the first 500 fs. The origin of the observed experimental temperature dependence is discussed in this context.

New theoretical investigations of the photodissociation of ozone in the Hartley, Huggins, Chappuis, and Wulf bands

“…4 had been constructed before by Hay et al, 27 Sheppard and Walker, 28 and Yamashita et al 29 They have been crucial for establishing the qualitative one-state picture of the dissociation dynamics. [69][70][71][72][73][74] However, because of insufficient accuracy, the experimental data, especially the vibrational and rotational state distributions of O 2 in the singlet channel, have not been satisfactorily reproduced in these early calculations. Parallel to our work, Baloı¨tcha and Balint-Kurti 75,76 also calculated the energies of the five lowest 1 A 0 states of ozone, using almost the same level of electronic structure theory and the same approximate diabatization procedure as in our work.…”

“…The results show that the cold spectrum is definitely more structured than the 195 K absorption spectrum. The second missing point in all theoretical models up to now is the possibility of non-adiabatic transitions to other electronic states, primarily A and R. Several authors speculated 63,69,72 that non-adiabatic coupling would accelerate the decay, reduce the resonance wave functions near the saddle, and thereby decrease the amplitudes of recurrences. However, since the global potentials for the crossing states have been calculated only a year ago, 63 this suggestion could not be seriously investigated until recently.…”

The photodissociation of ozone in the Hartley band: A theoretical analysis

“…Because of the enormous progress in computer technology and refinements of electronic structure methods, significant improvements have been made every ten years or so. It has been used in several dynamics studies to interpret the diffuse structures superimposed on the bell-shaped absorption spectrum 28,38,39 and to calculate the vibrational-rotational state distributions of O 2 ͑a 1 ⌬ g ͒. The second B-state PES was constructed by Leforestier et al 28 ͓Leforestier, Le Quéré, Yamashita, and Morokuma ͑LLYM͔͒.…”

Theory of the photodissociation of ozone in the Hartley continuum; effect of vibrational excitation and O(1D) atom velocity distribution

“…though more detailed investigation shows that other break-up products are also formed with smaller probabilities. 13 Due to its great importance there have been many experimental 1,2,4-27 and theoretical [28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47] investigations of the photodissociation of ozone in the Hartley continuum. We have recently computed potential energy and transition dipole moment surfaces for the lowest five 1 A 0 electronic states of the system.…”