Comparison of conventional ab initio and density functional methods for the ArHF interaction potential

Abstract

The geometry and interatomic potential for the ground state of ArHF was determined by HF, MP2, MP4, QCISD and density functional theory (DFT) methods using 6-311G ∗∗ basis set. It was found that there is no agreement between conventional ab initio and DFf methods. Of the two possible conformers investigated in this study, ArHF complex is found to be more stable than the ArFH complex. The present study indicates that the calculated binding energy and geometrical parameters depend on the choice of various density functionals used in the DFT calculation. The results indicate that the 6-311G ∗∗ basis set is not sufficient to reproduce the experimental binding energy and geometry. Addition of diffuse and polarizable functions in the basis set may enhance the quality of prediction.