Does Basis Set Superposition Error Significantly Affect Post-CCSD(T) Corrections?

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 QΛ-Q$$ {(Q)}_{\Lambda}-(Q) $$ or T4-Q$$ {T}_4-(Q) $$ especially so. In contrast, for atomization energies, the T3-T$$ {T}_3-(T) $$ counterpoise correction can reach about 0.05 kcal/mol 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 T3-T$$ {T}_3-(T) $$ applied in bo

SUBMITTER: Fishman V 

PROVIDER: S-EPMC11668233 | biostudies-literature | 2025 Jan

REPOSITORIES: biostudies-literature