# A variationally computed room temperature line list for AsH$_{3}$

## TL;DR

This paper presents a highly accurate variational calculation of the rotation-vibration energy levels and transition intensities of arsine (AsH₃), resulting in a comprehensive line list at room temperature that aligns well with experimental data.

## Contribution

The study introduces a refined potential energy surface and a new dipole moment surface for AsH₃, enabling precise computation of energy levels and transition intensities up to 10,500 cm⁻¹ and J=30.

## Key findings

- Energy levels match experimental data within 0.122 cm⁻¹ RMS error.
- Calculated line intensities agree within 10% with experimental measurements.
- Absorption cross-sections align well with laboratory spectra.

## Abstract

Calculations are reported on the rotation-vibration energy levels of the arsine molecule with associated transition intensities. A potential energy surface (PES) obtained from \textit{ab initio} electronic structure calculations is refined to experimental data, and the resulting energy levels display sub-wavenumber accuracy for all reliably known $J=0$ term values under 6500 cm$^{-1}$. After a small empirical adjustment of the band centres, our calculated ($J=1-6$) rovibrational states reproduce 578 experimentally derived energies with a root-mean-square error of 0.122 cm$^{-1}$. Absolute line intensities are computed using the refined PES and a new dipole moment surface (DMS) for transitions between states with energies up to 10~500 cm$^{-1}$ and rotational quantum number $J=30$. The computed DMS reproduces experimental line intensities to within 10\% uncertainty for the $\nu_1$ and $\nu_3$ bands. Furthermore, our calculated absorption cross-sections display good agreement with the main absorption features recorded in Pacific Northwest National Laboratory (PNNL) for the complete range of $600-6500$ cm$^{-1}$.