Abstract: Ab initio calculations at the MP2 and CCSD(T) levels of theory were performed to analyze the equilibrium structure and vibrational spectra of HXeBr compound. The calculated vibrational frequencies, corrected for anharmonicity and matrix effects, are 1492 cm^-1(H—Xe stretching), 509 cm^-1(bending) and 174 cm^-1(Xe—Br stretching). These are in good agreement with the observed values. The energetic stabilities and decomposition channels(HXeBr→Xe+HBr and HXeBr→H+Xe+Br) are calculated via single-configurational CCSD(T) and multireference averaged quadratic coupled-cluster(MR-AQCC) methods, respectively. The calculation results indicate that the energy barrier for HXeBr→Xe+HBr and HXeBr→H+Xe+Br is 1.39 and 0.89 eV, respectively. The three-body decomposition channel is found to be the dominate decomposition channel for HXeBr.

Key words: Compound HXeBr, Vibrational frequency, Decomposition Channel