A (2)A(2)<-(XB1)-B-2 absorption and Raman spectra of the OClO molecule: A three-dimensional time-dependent wave packet study

Time-dependent wave packet calculations of the (A (2)A(2)<--X B-2(1)) absorption and Raman spectra of the OClO molecule are reported. The Fourier grid Hamiltonian method in three dimensions is employed. The X B-2(1) ground state ab initio potential energy surface reported by Peterson [J. Chem. Phys. 109, 8864 (1998)] is used together with his corresponding A (2)A(2) state surface or the revised surface of the A (2)A(2) state by Xie and Guo [Chem. Phys. Lett. 307, 109 (1999)]. Radau coordinates are used to describe the vibrations of a nonrotating OClO molecule. The split-operator method combined with fast Fourier transform is applied to propagate the wave function. We find that the ab initio A (2)A(2) potential energy surface better reproduces the detailed structures of the absorption spectrum at long wavelength, while the revised surface of the A (2)A(2) state, consistent with the work of Xie and Guo, better reproduces the overall shape and the energies of the vibrational levels. Both surfaces of the A (2)A(2) state can reasonably reproduce the experimental Raman spectra but neither does so in detail for the numerical model employed in the present work. (C) 2005 American Institute of Physics