A larger basis set describes atomization energy core-valence correction better than a higher-order coupled-cluster method.

Autor: Chamkin AA; A.N.Nesmeyanov Institute of Organoelement Compounds of Russian Academy of Sciences Russia, Vavilova St. 28, bld. 1, INEOS, 119334, Moscow, Russian Federation. chalex@ineos.ac.ru., Chamkina ES; A.N.Nesmeyanov Institute of Organoelement Compounds of Russian Academy of Sciences Russia, Vavilova St. 28, bld. 1, INEOS, 119334, Moscow, Russian Federation. chalex@ineos.ac.ru.
Jazyk: angličtina
Zdroj: Physical chemistry chemical physics : PCCP [Phys Chem Chem Phys] 2023 Oct 18; Vol. 25 (40), pp. 27438-27447. Date of Electronic Publication: 2023 Oct 18.
DOI: 10.1039/d3cp03893a
Abstrakt: The accuracy of coupled-cluster methods for the computation of core-valence correction to atomization energy was assessed. Truncation levels up to CCSDTQP were considered together with (aug-)cc-pwCV n Z ( n = D, T, Q, 5) basis sets and three different extrapolation techniques (canonical and flexible Helgaker formula and Riemann zeta function extrapolation). With the exception of CCSD, a more accurate correction can be obtained from a larger basis set using a lower-level coupled-cluster method, and not vice versa . For the CCSD(T) level, it also implies faster computations with modern codes. We also discussed the importance of moving to higher-order or all-electron methods for geometry optimizations. The present study provides the general knowledge needed for the most accurate state-of-the-art computations.
Databáze: MEDLINE