First Principles Rovibronic Absorption Spectra of HF Molecule.

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 B 1 Σ + - X 1 Σ + $$ {\mathrm{B}}^1{\Sigma}^{+}-{\mathrm{X}}^1{\Sigma}^{+} $$ and C 1 Π - X 1 Σ + $$ {\mathrm{C}}^1\Pi -{\mathrm{X}}^1{\Sigma}^{+} $$ 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 ( τ v ' $$ {\tau}_{v^{\prime }} $$ ) for the B 1 Σ + - X 1 Σ + $$ {\mathrm{B}}^1{\Sigma}^{+}-{\mathrm{X}}^1{\Sigma}^{+} $$ and C 1 Π - X 1 Σ + $$ {\mathrm{C}}^1\Pi -{\mathrm{X}}^1{\Sigma}^{+} $$ 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.