Interaction dipole moment in Rg-Xe (Rg = He, Ne, Ar, and Kr) heterodiatoms from conventional ab initio and density functional theory calculations

摘要

We have obtained interaction dipole moment curves for the rare gas heterodiatoms Rg... Xe (Rg=He, Ne, Ar, and Kr) from conventional ab initio and density functional theory calculations with flexible Gaussian-type basis sets. All methods seem to reproduce fairly similar dipole moment curves for all pairs. Our best values for the interaction dipole moment ( at the respective experimental equilibrium separation R-e) were obtained at the coupled-cluster theory with single, double, and perturbatively linked triple excitations level of theory: mu(int)(RgXe)/ e alpha(0) = - 0.0025(He),- 0.0047(Ne), - 0.0055(Ar), and - 0.0037 (Kr). The same trend ( in absolute terms) is observed at the MP2 level of theory for the derivative of the dipole moment at R-e, as (d mu(int)(RgXe)/dR)(e)/e = 0.0043 (He), 0.0082 (Ne), 0.0091 (Ar), and 0.0059 (Kr). Around R-e, mu(int)(HeXe) = mu(HeXe) varies at the MP2 level of theory as [mu(HeXe)(R) - mu(HeXe)(R-e)]/ ea(0) = 0.0043(R-R-e)- 0.0033(R- R-e)(2)+ 0.0018(R- Re)(3)- 0.0005(R- R-e)(4).