Quantum calculations of highly excited vibrational spectrum of sulfur dioxide. III. Emission spectra from the C 1B2 state

Abstract

We report quantum mechanical calculations of the X̃←C̃ emission spectra of SO2 at the red wing of the C̃ absorption band. The near equilibrium potential energy surface of the C̃ 1B2 state is deduced by fitting experimental vibrational frequencies using an exact quantum mechanical Hamiltonian. Low-lying vibrational eigenenergies on this double minimum potential agree well with experimental frequencies and the corresponding eigenstates show some interesting features. Both spectral positions and intensities of the X̃←C̃ transitions are obtained up to 16 000 cm−1 using a Chebyshev based spectral method, which does not explicitly construct vibrational eigenfunctions in the X̃ state. The emission spectra are in reasonably good agreement with experimental measurements.