Jacob, FortunatusPogrebnaya, Tatiana P.Pogrebnoi, Alexander M.2024-06-172024-06-172016-12-27https://repository.udsm.ac.tz/handle/123456789/6081The structure and thermodynamic properties of cluster ions detected earlier in saturated vapour over barium dibromide were studied theoretically. The equilibrium geometrical parameters and vibrational spectra were computed for the ions BaBr3 , Ba2Br3 + , Ba3Br5 + , Ba4Br7 + and Ba5Br9 + ; the DFT and MP2 methods with triple-zeta valence basis sets were used. The enthalpies of ion molecular reactions were obtained both theoretically through the total energies of participants and based on experimental data. The theo retical results were scrutinized with respect to methods of computation (DFT, MP2, and MP4). The enthalpies of formation DfHo (0) of the ions have been determined (in kJ mol 1 ): 858 ± 6 (BaBr3 ); 293 ± 10 (Ba2Br3 + ); 982 ± 20 (Ba3Br5 + ); 1644 ± 30 (Ba4Br7 + ); 2282 ± 17 (Ba5Br9 + ).enBarium dibromideCluster ionsDFTMP2MP4Geometrical structureVibrational spectraEnthalpies of ion molecular reactionsEnthalpies of formationThermodynamic functionsJournal Articlehttps://doi.org/10.1016/j.comptc.2016.12.035