Theoretical investigations of the nature of interaction of Br2 with hydrogen halide

The interactions of the Br2 with hydrogen halide have been investigated by performing calculations at the second-order perturbation theory based on the Møller-Plesset partition of the Hamiltonian with the Sadlej PVTZ basis set. The X-Br type geometry and hydrogen-bonded geometry are investigated in these interactions. The calculated interaction energies show that the X-Br type structures are more stable than the corresponding hydrogen-bonded structures. To study the nature of the intermolecular interactions, symmetry-adapted perturbation theory (SAPT) calculations were carried out and the results indicate that the X-Br interactions are dominantly electrostatic and dispersion energy in nature, while dispersion energy governs the hydrogen bonding interactions.