Semiclassical vibrational eigenvalues of triatomic molecules: Application of the FFT method to SO2, H2O, H+3, and CO2

摘要

We have applied a recently developed fast Fourier transform method for determining vibrational action variables to the calculation of semiclassical eigenvalues for SO2, H2O, H+3, and CO2(all for zero rotational angular momenta). The results for SO2and H2O are essentially equivalent in accuracy to results from previous semiclassical applications. H+3and CO2, on the other hand, have not been studied previously by semiclassical methods, in part because of the 1:1 and 2:1 resonances respectively present in these molecules. The results of the present calculations are in reasonable agreement with quantum eigenvalues which have been calculated for H+3and CO2, with errors which are consistent with those obtained for H2O and SO2.