We have developed a mixed classical-quantum dynamical simulation of HCl diluted in dense Ar in which both the rotation and vibration of the diatomic molecule are treated from a quantum point of view while the remaining translational degree of freedoms of the diatomic and solvent atoms, are treated classically. We have calculated the spectral density of the fundamental band and the rotational absorption coefficient of HCl in Ar at different thermodynamic conditions and we have compared them with the available experimental data. Unlike our previous simulation works on HCl in Ar, in this study we treat the diatomic vibration explicitly, so we can carry out a detailed theoretical experimental comparative analysis of the spectral profiles. We have considered different models for the HCl Ar binary anisotropic interaction, founding also different predictions for the absorption line shape, in one case with the presence of the central Q-branch observed in the experimental spectrum, and in another case with the absence of such spectral component. We have found that the theoretical Q-branch noticeably depends on the characteristic of the different anisotropic diatomic-solvent potentials proposed in the literature. (C) 2015 Elsevier Inc. All rights reserved.
