Место издания:Publishing House of IAO SB RAS Tomsk
Первая страница:86
Последняя страница:86
Аннотация:The HITRAN 2016 [1] and ExoMol [2] databases contain the CO spectroscopic data evaluated using the empirical potential energy function (PEF) due to Coxon and Hajigeorgiou [3] and hybrid empirical/ab initio dipole moment function (DMF) due to Li et al. [4]. The functions above reproduce the observed ro-vibrational line positions and their intensities with the experimental accuracy. However, they could not provide the reliable intensities for very weak transitions corresponding to higher overtones [5] and anomalies [6].
In order to reach “completeness in both vibrational and rotational states” [7] for the CO molecule, which means modeling of the allowed optical transitions between all bound ro-vibrational levels at least of the ground electronic state, we recently constructed a fully analytical semi-empirical PEF [5] which demonstrates the physically justified behavior in both asymptotic limits. Here, we make the next step and build a semi-empirical DMF obeying the same requirements. The input experimental intensity data were borrowed both from early studies and recent investigations. The united-atom limit was described analytically due to Buldakov et al. [8] whereas the experimentally “dark” region and the long-range limit were reconstructed by means of high level ab initio calculations accomplished in the entire range of inter-atomic distance.
The work was supported by the Russian Science Foundation; grant N 18-13-00269.