A new ro-vibrational line list for the ground electronic state of the main isotopologue of acetylene, 12C2H2, is computed as part of the ExoMol project. The aCeTY line list covers the transition wavenumbers up to 10,000 cm−1 (λ>1μm), with lower and upper energy levels up to 12,000 cm−1 and 22,000 cm−1 considered, respectively. The calculations are performed up to a maximum value for the vibrational angular momentum, Kmax=Lmax = 16, and maximum rotational angular momentum, J = 99. Higher values of J were not within the specified wavenumber window. The aCeTY line list is considered to be complete up to 2200 K, making it suitable for use in characterising high-temperature exoplanet or cool stellar atmospheres. Einstein-A coefficients, which can directly be used to calculate intensities at a particular temperature, are computed for 4.3 billion (4,347,381,911) transitions between 5 million (5,160,803) energy levels. We make comparisons against other available data for 12C2H2, and demonstrate this to be the most complete line list available. The line list is available in electronic form from the online CDS and ExoMol databases.
@article{arxiv.2001.04550,
title = {ExoMol molecular line lists -- XXXVII: spectra of acetylene},
author = {Katy L. Chubb and Jonathan Tennyson and Sergey N. Yurchenko},
journal= {arXiv preprint arXiv:2001.04550},
year = {2020}
}