First Principles Rovibronic Absorption Spectra of HF Molecule

Area of Science:

• Quantum Chemistry and Spectroscopy
• Computational Physics
• Astrophysical Chemistry

Background:

• Accurate spectroscopic data for molecules like hydrogen fluoride (HF) are essential for interpreting observations in various astrophysical environments.
• Previous experimental data for HF rovibronic spectroscopy is limited, necessitating theoretical calculations to fill the gap.
• Understanding the electronic structure and nuclear motion of diatomic molecules is fundamental to molecular spectroscopy.

Purpose of the Study:

• To perform an ab initio study of the rovibronic spectroscopy of the hydrogen fluoride (HF) molecule.
• To generate comprehensive line lists for the B 1Σ+–X 1Σ+ and C 1Π–X 1Σ+ band systems of HF.
• To simulate temperature-dependent rovibronic absorption cross sections and compare them with experimental data.

Main Methods:

• High-level electronic structure computations were employed to determine the potential energy surfaces.
• Accurate calculations of the Schrödinger equation for nuclear motion were performed.
• A combination of empirical and ab initio methods was used to construct the spectroscopic model and line lists.

Main Results:

• Generated line lists covering the B 1Σ+–X 1Σ+ and C 1Π–X 1Σ+ band systems of HF.
• Simulated temperature-dependent rovibronic absorption cross sections, showing good agreement with available experimental data.
• Calculated radiative lifetimes for the B and C states, consistent with previous theoretical and experimental results.

Conclusions:

• The developed spectroscopic model and line lists for HF are reliable and validated against experimental data.
• The generated data can be used for spectroscopic modeling of HF in interstellar space and planetary atmospheres.
• This work provides essential data for the interpretation of astronomical observations involving hydrogen fluoride.