A computational inspection of the dissociation energy of mid-sized organic dimers

0557643 - ÚMCH 2023 RIV US eng J - Journal Article
Czernek, Jiří - Brus, Jiří - Czerneková, Vladimíra
A computational inspection of the dissociation energy of mid-sized organic dimers.
Journal of Chemical Physics. Roč. 156, č. 20 (2022), č. článku 204303. ISSN 0021-9606. E-ISSN 1089-7690
R&D Projects: GA ČR(CZ) GA20-01233S
Research Infrastructure: e-INFRA CZ - 90140; ELIXIR-CZ - 90047
Institutional support: RVO:61389013 ; RVO:68378271
Keywords : noncovalent interactions * dissociation energy * DFT-D
OECD category: Polymer science; Physical chemistry (FZU-D)
Impact factor: 4.4, year: 2022
Method of publishing: Limited access
https://aip.scitation.org/doi/10.1063/5.0093557

The gas-phase value of the dissociation energy (D0) is a key parameter employed in both experimental and theoretical descriptions of noncovalent complexes. The D0 data were obtained for a set of mid-sized organic dimers in their global minima which was located using geometry optimizations that applied ample basis sets together with either the conventional second-order Møller–Plesset (MP2) method or several dispersion-corrected density-functional theory (DFT-D) schemes. The harmonic vibrational zero-point (VZP) and deformation energies from the MP2 calculations were combined with electronic energies from the coupled cluster theory with singles, doubles, and iterative triples [CCSD(T)] extrapolated to the complete basis set (CBS) limit to estimate D0 with the aim of inspecting values that were most recently measured, and an analogous comparison was performed using the DFT-D data. In at least one case (namely, for the aniline⋯methane cluster), the D0 estimate that employed the CCSD(T)/CBS energies differed from experiment in the way that could not be explained by a possible deficiency in the VZP contribution. Curiously, one of the DFT-D schemes (namely, the B3LYP-D3/def2-QZVPPD) was able to reproduce all measured D0 values to within 1.0 kJ/mol from experimental error bars. These findings show the need for further measurements and computations of some of the complexes. In order to facilitate such studies, the physical nature of intermolecular interactions in the investigated dimers was analyzed by means of the DFT-based symmetry-adapted perturbation theory.
Permanent Link: http://hdl.handle.net/11104/0331913