Gaussian-based range-separation approach on Hartree–Fock exchange interaction and second-order perturbation theory

Highlights: • Gaussian-based and erfc short-range potentials for perturbation theory. • Gaussian short-range potential yields better similarity to the bare potential. • Gaussian cutoff reproduces the HF and MP2 methods well. A Gaussian-based range-separation approach is applied to the Hartree–Fock exchange interaction and the second-order perturbation theory, comparing the results with those provided through the erfc short-range potential approach. The Gaussian short-range potential's behavior resembles more that of the bare 1/r potential than that of the erfc short-range potential around the origin. Thus, the Gaussian-based range-separation of the exchange term agrees better with the ordinary HF method and the Møller–Plesset perturbation theory.