Self-consistent basis set extrapolation of Hartree-Fock energies

A self-consistent approach is proposed for the basis set extrapolation of Hartree-Fock (HF) energies. Similar to existing extrapolation techniques, our scheme is based on convergent basis set hierarchies such as correlation-consistent basis sets. However, unlike the former, which utilize two or more HF energies obtained in separate HF calculations, the present method approximates the complete basis set limit HF energy in a single self-consistent field calculation minimizing a simple energy functional. Our benchmark results demonstrate that the performance of the self-consistent extrapolation approach is very similar to that of the conventional ones. The major advantage of the self-consistent technique is that the variational nature of the extrapolated energy facilitates the evaluation of analytic derivatives.