New basis sets for the evaluation of interaction energies: an ab initio study of the He–He, Ne–Ne, Ar–Ar, He–Ne, He–Ar and Ne–Ar van der Waals complex internuclear potentials and ro-vibrational spectra

摘要: We investigated the performance of medium-size basis sets in calculations interaction energies for small van der Waals complexes. After careful numerical tests we derived new efficient (modified LPol-n bases, MLPol-n) evaluation He-He, Ne-Ne, Ar-Ar, He-Ne, He-Ar and Ne-Ar Additionally, carried out systematic set studies taking as a starting point Jensen's aug-pc-2 set. In both cases considered addition midbond functions to bases. The proposed MLPol-n use model harmonic oscillator embedded an external electric field belong family Pol quality was first tested through finite-field Hartree-Fock atomic polarizability calculations. Next obtained coupled cluster singles doubles (CCSD), including connected triples, CCSD(T), potentials six complexes, reference most accurate theoretical values available literature, implemented energies. To test further used them calculate ro-vibrational spectra results are very good agreement with experimental data. future, plan extend study larger