# First Principles Rovibronic Absorption Spectra of HF Molecule

## TL;DR

This paper presents a detailed computational study of the HF molecule's rovibronic absorption spectra, useful for understanding its behavior in astrophysical environments.

## Contribution

The study provides new ab initio line lists and validated absorption cross sections for HF spectroscopy.

## Key findings

- Simulated absorption cross sections show overall consistency with experimental data.
- Calculated radiative lifetimes for specific band systems are reported.
- Line lists are suitable for modeling HF in astrophysical media.

## Abstract

An ab initio study on the rovibronic spectroscopy of the hydrogen fluoride HF molecule is reported based on using high‐level electronic structure computations and accurate calculations of the Schrödinger equation for the nuclear motion. A combination of empirical and ab initio methods is used to generate a spectroscopic model and a corresponding line list of the HF molecule. The line lists cover the and band systems. Rovibronic absorption spectra are simulated in the form of temperature‐dependent cross sections for these bands. Comparisons between our simulated absorption cross section and the available experimental ones show overall consistency. Calculated radiative lifetimes (τv′) for the and systems are compared to previous results. Given the scarcity of published rovibronic experimental data on this molecule, the line lists can be used for spectroscopic modeling of HF in astrophysical media, including interstellar space, planetary and exoplanetary atmospheres.

Hydrogen fluoride (HF) is astrophysically important, as it has been detected in sunspots, Venus, red giants, and the interstellar medium, serving as a probe of exoplanet atmospheres. This article presents an ab initio investigation of HF rovibronic spectroscopy, combining high‐level electronic‐structure data with nuclear‐motion solutions and refinement to produce validated line lists. Temperature‐dependent absorption cross sections are simulated and agree with measurements. Radiative lifetimes are calculated, enabling interpretation and modeling in astrophysical environments.