Evaluation of the coupled-cluster correction term, δCCSD(T)MP2, calculated using small valence basis sets.
In the focal-point estimation of the coupled cluster with singles, doubles, and perturbative triples [CCSD(T)] interaction energies followed by extrapolation to the complete basis set (CBS) limit, the most critical and challenging step is the rapid and accurate calculation of the coupled-cluster correction term, δMP2CC...