Structure, energetics, and spectroscopy of the K2+(X2Σ+g) interacting with the noble gas atoms Ar, Kr and Xe

Abstract

The structure, energetic, and spectroscopy properties of the ionic system K₂⁺(X²Σ⁺_g) interacting with the noble gas atoms Argon, Krypton and Xenon are studied. The computations are done by an accurate ab initio approach based on the pseudo-potential technique, Gaussian basis sets, parameterized l-dependent polarization potentials and an analytic potential form for the K⁺Ar, K⁺Kr and K⁺Xe interactions. These interactions are added via the CCSD(T) potential taken from literature and fitted applying the analytical expression of Tang and Toennies. The application of the pseudo-potential approach reduces the number of active electrons of each complex to only one electron. The potential energy surfaces are analyzed on a large range of the Jacobi coordinates, R and θ. By the general interpolation outline based on the RKHS (Reproducing Kernel Hilbert Space) procedure, we have reproduced for each complex from our ab initio results the two-dimensional contour plots of an analytical potential. To evaluate the stability of each complex, we have determined from the potential energy surfaces the equilibrium distance (R_e), the well depth (D_e), the quantum energy (D₀), the zero-point-energy (ZPE) and the ZPE%. The results showed that the linear configurations, where the noble gas atom connected to the K₂⁺(X²Σ⁺_g) system, are the more stable.