# A pedagogical description of diabatic and adiabatic molecular processes

## TL;DR

This paper offers an educational explanation of diabatic and adiabatic molecular processes, focusing on avoided crossings and electronic state transitions in diatomic molecules with classical nuclear motion.

## Contribution

It presents a simplified, pedagogical approach to understanding avoided crossings and electronic transitions in diatomic molecules, limited to two electronic states.

## Key findings

- Clarifies the concepts of diabatic and adiabatic transitions.
- Provides a step-by-step explanation of avoided crossings.
- Focuses on classical nuclear motion in diatomic molecules.

## Abstract

We provide a pedagogical approach to the problem of avoided crossings between electronic molecular curves and to diabatic and adiabatic transitions when the nuclei of a diatomic molecule move according to classical mechanics. For simplicity we restrict the analysis to only two electronic states.