Resonance spectrum and dissociation dynamics of ozone in the B23 electronically excited state: Experiment and theory

Abstract

The rovibrational spectrum assigned to the low-lying (3)B(2) electronic state of ozone is measured with intracavity laser absorption spectroscopy. The experimental results are interpreted by means of quantum dynamical calculations on a global ab initio potential energy surface. The observed spectrum is shown to originate from the vibrational ground state in the local minimum of the (3)B(2) potential. The spectrum of short-lived resonance states in this local minimum is analyzed. Additionally, the global minimum of the surface is shown to lie in the dissociation channel in the van der Waals region. This region supports a short sequence of weakly bound vibrational states.

Absorption spectrum and assignment of the Chappuis band of ozone

“…13 In the past few years, our group began a comprehensive theoretical investigation of the photoabsorption spectrum of ozone. [14][15][16][17][18][19][20][21] To this end, new global potential energy surfaces ͑PESs͒ of the electronically excited states of ozone were calculated, all at the same ͑high͒ level of the electronic structure theory. Quantum mechanical absorption spectra for the new PESs have recently been reported for the uv Hartley and Huggins bands ͑3 1 AЈ electronic state͒ and for the weak subband of the Wulf band system associated with the 3 B 2 electronic state.…”

Spin-orbit mechanism of predissociation in the Wulf band of ozone

“…Deppe et al studied the resonance spectrum of the 3 B 2 electronic state using a global PES. 11 Experimentally, the transition to this state shows up as a single weak structure superimposed on the low-energy tail of the stronger band 2 0 2 of state 3 A 2 . In agreement with this observation, the shallow minimum ͑depth Ϸ550 cm −1 ͒ of the 3 B 2 PES was found to support only one narrow resonance near 10 200 cm −1 assigned as ͑0,0,0͒.…”

“…11 In both calculations the vibrational ground states, trapped behind a barrier, could dissociate only through a narrow transition state to the continuum of the electronic state in question. Coupling to isoenergetic continua of other electronic states, which opens alternative decay paths, was ignored.…”

“…However, in this case the individual linewidths are too large to allow determination of ⌫͑J , K͒; only an average width has been obtained. 11 Two ab initio studies of the electronic states involved in the Wulf transitions were recently published. Xie et al investigated the low lying resonances of the nonadiabatically coupled 3 A 2 and 3 B 1 states using near-equilibrium potential energy surfaces ͑PESs͒.…”

“…The three-dimensional ͑3D͒ PESs of the ground electronic state ͑V X ͒ and the 3 AЈ state ͑V A Ј ͒ are taken from previous calculations. 11,16 The 3D PES of the lowest adiabatic state 1 3 AЉ ͑V A Љ ͒ is calculated in this work at the internally-contracted multireference configuration interaction ͑MR-CI͒ singles and doubles level 17 ͑including the Davidson correction͒ using Dunning's augmented correlation consistent polarized valence triple zeta ͑aug-cc-pVTZ͒ basis. 18 The wave functions are based on state-averaged complete active space self-consistent field ͑CASSCF͒ calculations with a full-valence active space.…”