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Physical nature of silane⋯carbene dimers revealed by state‐of‐the‐art ab initio calculations
Author(s) -
Yourdkhani Sirous,
Jabłoński Mirosław
Publication year - 2019
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.26043
Subject(s) - extrapolation , carbene , basis set , ab initio , limit (mathematics) , silane , counterpoise , dispersion (optics) , chemistry , convergence (economics) , computational chemistry , interaction energy , ab initio quantum chemistry methods , thermodynamics , atomic physics , physics , quantum mechanics , molecule , density functional theory , mathematics , mathematical analysis , organic chemistry , economics , economic growth , catalysis
Using the SAPT2 + 3(CCD) δ MP2 method in complete basis set (CBS) limit, it is shown that the interactions in the recently studied silane⋯carbene dimers are mainly dispersive in nature. Consequently, slow convergence of dispersion energy also forces slow convergence of the interaction energy. Therefore, obtaining very accurate values requires extrapolation of the correlation part to the CBS limit. The most accurate values obtained at the CCSD(T)/CBS level of theory show that the studied silane⋯carbene dimers are rather weakly bound, with interaction energies ranging from about −1.9 to −1.3 kcal/mol. Comparing to CCSD(T)/CBS, it will be shown that SCS‐MP2 and MP2C methods clearly underestimate and methods based on SAPT2+ and having some third‐order corrections, as well as the MP2 method, overestimate values of interaction energies. Popular SAPT(DFT) method performs better than SCS‐MP2 and MP2C; nevertheless, underestimation is still considerable. The underestimation is slightly quenched if third‐order dispersion energy and its exchange counterpart is added to the SAPT(DFT). The closest value of CCSD(T)/CBS has been given by the SAPT2 + (3)(CCD) δ MP2 method in quadruple‐ ζ basis set. © 2019 Wiley Periodicals, Inc.