# Evaluating the interactions between vibrational modes and electronic transitions using frontier orbital energy derivatives

## TL;DR

The paper introduces a low-cost computational method to identify vibrations strongly linked to electronic structure using orbital energy derivatives.

## Contribution

A novel low-cost method is proposed to identify vibrations coupled to electronic structure using frontier orbital energy derivatives.

## Key findings

- Vibrational effects on electronic transitions can be modeled even at zero kelvin.
- Frontier orbital energy derivatives serve as a diagnostic for identifying strongly coupled vibrations.
- The proposed method reduces computational cost by avoiding many geometry-distorted calculations.

## Abstract

Vibrations affect molecular optoelectronic properties, even at zero kelvin. Accounting for these effects using computational modelling is costly, as it requires many calculations at geometries distorted from equilibrium. Here, we propose a low-cost method for identifying vibrations most strongly coupled to the electronic structure, based on using orbital energy derivatives as a diagnostic.

Frontier orbital energy derivatives can be used to identify vibrations strongly coupled to electronic structure.