New potential energy surfaces for the complexes Ar–CuX (X = F, Cl, Br, and I)

Abstract

New intermolecular potential energy surfaces (PESs) are constructed at the level of the non-iterative perturbation treatment of triple excitations [CCSD(T)] plus aug-cc-pVQZ basis set supplemented with bond functions for the complexes Ar–CuX (X = F, Cl, Br, and I) at the rigid rotor approximation. The global minimum is assigned to be a collinear Ar–Cu–X geometry, while the local minimum is an anti-linear Cu–X–Ar geometry on the PES for each complex. Based on the PESs, the intermolecular vibrations, pure rotational spectra, as well as isotope effects are investigated via the bound state calculations. We also give a detailed comparison of the structural parameters, binding energies, accuracy of PESs, as well as the results of basis set superposition error (BSSE) correction with those of Ar–AgX complexes. In addition, we construct a three-dimension (3D) intermolecular PES for the complex Ar–CuF, which not only gives the information of structural change for Cu―F distance upon the complex formation, but also reproduces the rotational spectroscopic characteristics much better.