HXeBr in CO2 and Xe environments is modeled at the B3LYP-D level of theory, using a full single shell of CO2 molecules and Xe atoms around the HXeBr molecule. For the CO2 environment, the optimized structure indicates a double substitutional site in the otherwise approximately preserved structure of solid CO2. The calculated vibrational spectra and energetic properties indicate strong interactions of HXeBr with the CO2 environment, which is significantly stronger than in the case of the Xe environment. The H-Xe stretching frequency obtained by a variant of the anharmonic VSCF method is in good accord with the available experimental data. (C) 2014 Elsevier B.V. All rights reserved.