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arXiv · 2408.10034

Does basis set superposition error significantly affect post-CCSD(T) corrections?

Vladimir Fishman·Emmanouil Semidalas·Margarita Shepelenko·Jan M. L. Martin
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Abstract

We have investigated the title question for both a subset of the W4-11 total atomization energies benchmark, and for the A24x8 noncovalent interactions benchmark. Overall, counterpoise corrections to post-CCSD(T) contributions are about two orders of magnitude less important than those to the CCSD(T) interaction energy. Counterpoise corrections for connected quadruple substitutions (Q) are negligible, and $(Q)_\Lambda - (Q)$ or $T_4 - (Q)$ especially so. In contrast, for atomization energies, the $T_3-(T)$ counterpoise correction can reach about 0.05 \kcalmol~for small basis sets like cc-pVDZ, thought it rapidly tapers off with cc-pVTZ and especially aug-cc-pVTZ basis sets. It is reduced to insignificance by the extrapolation of $T_3-(T)$ applied in both W4 and HEAT thermochemistry protocols. In noncovalent dimers, the differential BSSE on post-CCSD(T) correlation contributions is negligible even in basis sets as small as the unpolarized split-valence cc-pVDZ(no d).

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Vladimir Fishman, Emmanouil Semidalas, Margarita Shepelenko, Jan M. L. Martin. 2024-08-19. Does basis set superposition error significantly affect post-CCSD(T) corrections?. https://doi.org/10.1002/jcc.70007

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