Spectroscopic databases

Another important branch of our research activity is developing and populating spectroscopic databases that provide line-by-line reference molecular spectra. Our main direction in this field is providing collision induced line-shape parameters that are based on our accurate ab initio quantum-scattering calculations. For the simplest molecular system (He-perturbed molecular hydrogen), we provided full datasets of collision-induced line-shape parameters that cover all rovibrational transitions for both H2 [44] and HD [53] isotopologues. For the more complex systems of H2-perturbed H2 and HD lines we provided the results for the first several lines [69] with the long-term goal of populating the entire database as we did for the He-perturbed cases. At the moment our main interest concerns the line-shape calculations for several molecular systems that are relevant for the Earth atmosphere including: CO [54], O2 [48], HCl [66], HF and HCN [75] (for all these cases the relevant perturbers are N2 and O2 atoms). Another important direction that we work on is introducing to the spectroscopic databases collisional line-shape models which include beyond-Voigt effects such as speed dependence of the collisional broadening and shift and complex Dicke effect. In 2016, we started from developing the HITRAN database parameterization for the Hartmann-Tran profile [12]. In Ref. [39], we analyzed the problem of analytical representation of temperature dependencies of the line-shape parameter and recommended using the double power law approximation. Recently, we provided a detailed analysis of the Hartmann-Tran profile identifying some limitations, which led us to developing its modified version (modified Hartmann-Tran profile) [73], which is now the recommended beyond-Voigt profile in the HITRAN database. In parallel to the line-shape calculations, recently we got involved also in calculations of line intensities for simple diatomic molecules [70, 74]. These projects are pursued within a tight collaboration with the HITRAN group.