Absorption Spectra for SO2 Isotopologues

For a bending mode progression in a harmonic oscillator, the shifts in the band head locations upon sulfur isotope substitution are given by [25] 

Alternatively, band peak shifts can be computed from at) initio absorption spectra for SO2 isotopologues [28], which is the method I ve used here. The ah initio spectra were computed by time domain methods (Lanczos recursion and Cheby-shev propagation) using a new potential energy surface for SO2. The ah initio 

FIGURE 5.2 (a) High resolution SO2 absorption spectrum from 190 to 220 nm at 213 K [21]. Approximate spectrum for (blue) is also shown as a red-shifted version of the 

FIGURE 5.3 Normalized ab initio spectra for S02 (red) and S02 (blue) [28], and laboratory absorption spectra for 502 at 213 K (black) [21]. Note that the peaks of the vibrational progressions agree, but the ab initio spectra do not match well with the measured absorption continuum. The agreement between the ab initio and measured vibronic band locations deteriorates at wavelengths shortward of 200 nm. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this book.) 

FIGURE 5.4 Band shifts between S02 and as determined from Ran et al. [28] ab initio 

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