Explicitly correlated second order perturbation theory with frozen Gaussian-type geminals

Abstract

We report on the performance of the explicitly correlated second order perturbation theory with frozen Gaussian-type geminals. Components in the Hylleraas energy functional are analyzed using the ansatz based on the s-and p-wave cusp conditions for singlet and triplet pairs. It is shown that calculated correlation energies are improved substantially by the introduction of the frozen geminals. © Springer-Verlag Berlin Heidelberg 2003.