Franck-Condon factors and r-centroids for the (D1Π−X1Σ+) transition of SiS molecule using R-K-R-V potential

Turning points of the vibrating SiS molecule in the D¹Π and X¹Σ⁺ electronic states are evaluated using R-K-R-V method. Franck-Condon (FC) factors and r-centroids are computed for the $\text{(}\text{D}{}^1\text{Π?}\text{X}{}^1\text{Σ}{}^{\mathrm{+}}\text{)}$ transition of the molecule using wavefunctions appropriate to R-K-R-V potential energy curves. The results of the FC-factors vary in accordance with the estimated intensities and also satisfy the vibrational sum rule. The sequence difference Δr remains approximately constant in the computed r-centroids.