Theoretical methods for calculating rotational-vibrational-electronic transition intensities in triatomic molecules

TL;DR

This paper reviews quantum theoretical methods for calculating transition intensities in triatomic molecules, highlighting their importance as models for larger molecules and discussing unresolved issues in molecular spectroscopy.

Contribution

It presents a tutorial overview of theoretical methods for accurate energy, wavefunction, and transition intensity calculations in triatomic molecules.

Findings

Demonstrates several theoretical approaches for transition intensity calculations.

Highlights unresolved problems in modern molecular spectroscopy.

Uses triatomic molecules as minimal models for larger systems.

Abstract

This article covers few selected aspects of quantum theory of molecular rotations and vibrations. Triatomic molecules are the simplest systems, which show qualitative characteristics of larger polyatomic molecules. On the minimal example of triatomic molecules we demonstrate several theoretical methods used to calculate highly accurate rotational-vibrational-electronic energies, wavefunctions and transition intensities. The reader can view this article as a tutorial, by no means comprehensive, which still touches some of the unsolved problems in modern theoretical molecular spectroscopy.