Knowledge Bank

Efficient in applications in molecular spectroscopy local mode method was modified on the base of careful analysis of transformation coefficients $lN\alpha \lambda$ and properties of intramolecular potential function. Approach was applied to the $XY2(C2vsymmetry),XY3andZXY3(C3v),XY4(Td)$, and $X2Y2(D\infty h)$ molecules. It was shown, that even in the framework of strict local mode approach known in $literature1$ relations between some spectroscopic parameters should be improved. New relations between centrifugal distortion coefficients and some other fourth order spectroscopic parameters were obtained. It was shown, that the knowledge of centrifugal distortion coefficients of the ground vibrational states of above mentioned molecules gives possibility to predict with high enough accuracy both the band centers, and vibration-rotation energy spectra of deformational bands even in conditions of total absence of any initial experimental information about these deformational bands. Recommendations on possibilities of prediction of vibration-rotation spectra in excited vibrational states on the base of experimental information about lowest vibrational states are made. This work was supported by the grant of Russian Foundation of Fundamental Researches N94-02-03081-a.