Question

Q: Selection rule for perpendicular vibrations of Nonlinear triatomic vibrotori Symmetric tops​

Answer 1

Answer:

Molecular Parameters and Energy Level Formulation

The treatment of the rotational energy levels and transition frequencies for polyatomic molecules is more complicated than the formulations applied to diatomic molecules [2]. However, since triatomic molecules are the simplest class of polyatomic species, they demonstrate the simplest spectra and interactions that non-rigid polyatomic species are capable of exhibiting. The triatomic molecules can be readily divided into three types as characterized by their spectral properties. These three classes, linear molecules, non-linear molecules, and molecules having doublet (or multiple) ground electronic states, will be described separately and in that order, since each successive type shows increasingly complex interactions through their rotational spectra.