Comparison of high-level post-Hartree–Fock and DFT methods on the calculation of interaction-induced electric properties of Kr–He

Abstract We have calculated the interaction dipole moment and polarizability of the Kr–He pair with high-level ab initio methods and density functional theory (DFT) methods relying on a flexible, atom-specific basis set. High-order electron correlation effects are of some importance for internuclear separations up to the minimum of the interaction potential (R e ). At short distances the performance of ab initio and DFT methods is quite distinct. At the experimental separation R e  = 6.97309 a 0 and the highest level of theory CCSD(T), we estimate the interaction dipole moment, mean and anisotropy of the polarizability as μ  = 0.0017 ea 0 , α ¯ = - 0.019 and Δ α = 0.353 e 2 a 0 2 E h - 1 , respectively. The derivatives of interaction properties are d μ dR e = - 0.0028 e, d α ¯ dR e = 0.036 and d Δ a dR e = - 0.073 e 2 a 0 E h - 1 . The DFT methods offer a reasonable picture of the dipole moment and mean polarizability at R e but overestimate the magnitude of the anisotropy and its derivative.