This pull request addresses an issue regarding the basis sets of the 2022 ccECP paper (https://doi.org/10.1063/5.0087300). While working on the basis sets of the current ccECP manuscript, we noticed that in the previous paper, the elements Ag, Au, Pd, Mo, and W have an issue with polarization and core terms. Unfortunately, it seems the semi-core was not frozen when optimizing the cc-pVnZ basis sets, which would skew the polarization terms (f, g, h, i) towards higher values due to core excitations. Subsequently, the optimized core terms (C) for cc-pCVnZ would also be problematic as valence terms (V) already partially accounted for the core excitations. Overall, this might result in a non-systematic convergence of the correlation energy. This PR updates those terms for improved convergence.
A subsequent PR will add the ECPs and basis sets for the new ccECPs.
This pull request addresses an issue regarding the basis sets of the 2022 ccECP paper (https://doi.org/10.1063/5.0087300). While working on the basis sets of the current ccECP manuscript, we noticed that in the previous paper, the elements Ag, Au, Pd, Mo, and W have an issue with polarization and core terms. Unfortunately, it seems the semi-core was not frozen when optimizing the cc-pVnZ basis sets, which would skew the polarization terms (f, g, h, i) towards higher values due to core excitations. Subsequently, the optimized core terms (C) for cc-pCVnZ would also be problematic as valence terms (V) already partially accounted for the core excitations. Overall, this might result in a non-systematic convergence of the correlation energy. This PR updates those terms for improved convergence.
A subsequent PR will add the ECPs and basis sets for the new ccECPs.