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State‐of‐the‐art computations of dipole moments using analytic gradients of high‐level density‐fitted coupled‐cluster methods with focal‐point approximations
Author(s) -
Bozkaya Uğur,
Soydaş Emine,
Filiz Bahar
Publication year - 2020
Publication title -
journal of computational chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.907
H-Index - 188
eISSN - 1096-987X
pISSN - 0192-8651
DOI - 10.1002/jcc.26126
Subject(s) - coupled cluster , dipole , basis set , cluster (spacecraft) , computation , basis (linear algebra) , physics , method of moments (probability theory) , density functional theory , atomic physics , mathematics , quantum mechanics , algorithm , molecule , geometry , computer science , statistics , estimator , programming language
Using the analytic derivatives approach, dipole moments of high‐level density‐fitted coupled‐cluster (CC) methods, such as coupled‐cluster singles and doubles (CCSD), and coupled‐cluster singles and doubles with perturbative triples [CCSD(T)], are presented. To obtain the high accuracy results, the computed dipole moments are extrapolated to the complete basis set (CBS) limits applying focal‐point approximations. Dipole moments of the CC methods considered are compared with the experimental gas‐phase values, as well as with the common DFT functionals, such as B3LYP, BP86, M06‐2X, and BLYP. For all test sets considered, the CCSD(T) method provides substantial improvements over Hartree–Fock (HF), by 0.076–0.213 D, and its mean absolute errors are lower than 0.06 D. Furthermore, our results indicate that even though the performances of the common DFT functionals considered are significantly better than that of HF, their results are not comparable with the CC methods. Our results demonstrate that the CCSD(T)/CBS level of theory provides highly‐accurate dipole moments, and its quality approaching the experimental results. © 2019 Wiley Periodicals, Inc.