Two new ab initio IPESs were calculated at the RCCSD(T) level of theory employing aug-cc-pVXZ-33211 (X = T and Q) basis set for Ar–HCl complex. Supermolecular approach was used to calculate the interaction energies considering counterpoise correction for the basis sets superposition error (BSSE). The calculated interaction energies were analytically fitted to an analytical potential model. Both fitted potentials show a global and local minimum related to the linear Ar H–Cl and Ar Cl–H configuration, respectively which agree with the developed empirical potentials reported in literature. The interaction second virial coefficients and the rotational–vibrational spectroscopic properties of Ar HCl complex were obtained using the fitted potentials and compared with the available experimental data and the previous works in literature.
