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.