Theoretical study on the complexes of He, Ne and Ar

This paper investigates the effect of basis sets through the potential energy curves (PECs) of six rare gas complexes He₂, Ne₂, Ar₂, He–Ne, He–Ar, and Ne–Ar. The coupled cluster singles and doubles method with perturbative treatment of triple excitations, doubly augmented basis sets of d-aug-cc-pVQZ, bond functions, and basis set superposition errors are employed. The diffuse function is more effective than the polarization function on describing the dissociation energy. The PECs are fitted into analytical potential energy functions (APEFs) using three expressions. It is found that all the expressions are suitable for describing the complexes of rare gases. Based on these APEFs, the spectroscopic parameters are calculated and the results are compared with the theoretical and experimental data available in the literature.