Effects from Basis Sets and Levels of Calculations on the Nature of Interactions Predicted by QTAIM Dual Functional Analysis with QTAIM Functions

Abstract

Investigations concerning the nature of interactions must be considered an issue of primary importance in the chemical sciences. The dynamic and static natures of interactions were recently proposed based on the quantum theory of atoms in molecules dual functional analysis (QTAIM‐DFA). The nature of interactions is widely investigated under various conditions, which often results in the predictions of (very) different natures. The predicted nature should be well correlated to the observed parameters, especially for experimental scientists. The effects from the basis sets and levels of calculations on the predicted parameters are carefully examined, exemplified by the interaction distances in question, the QTAIM functions for the interactions, and the QTAIM‐DFA parameters. The effects are discussed for the total (basis set + level) terms and each term. The mechanisms of the total terms are also clarified for the QTAIM‐DFA parameters. The results provide a good guideline for discussion of the nature of interactions based on the calculated parameters under various calculation conditions. The results help to establish a reliable method to elucidate the nature of interactions, such as QTAIM‐DFA.

Intrinsic dynamic and static nature of each HB in the multi-HBs between nucleobase pairs and its behavior, elucidated with QTAIM dual functional analysis and QC calculations

“…The high similarities in r(H, B) correspond to the high similarities of the structures of Nu-Nu 0 optimized with the methods employed in the calculations. 43,46,55 The similarities are excellent, especially for the structures optimized with MP2/BSS-B 0 a, MP2/BSS-B 0 b and MP2/ BSS-A 0 , although frequency analysis could not be performed on those with MP2/BSS-A 0 .…”

Intrinsic Dynamic and Static Nature of π···π Interactions in Fused Benzene-Type Helicenes and Dimers, Elucidated with QTAIM Dual Functional Analysis

“…The results with M06-2X/6-311+G(3d,p) are discussed in the text, while the results with M06-2X/6-311+G(2d,p) and LC-ωPBE/6-311+G(2d,p) are discussed mainly in the Supporting Information . We should be careful with the basis set and level dependence on the QTAIM-DFA parameters, which has been examined carefully [ 53 ]. Similar methodology was also employed for the theoretical studies of the π-stacking [ 54 , 55 ].…”

The nature of G⋯E–Y σ(3c–4e) in o-MenGCH2C6H4EY (MenG = Me2N and MeE; E = O, S, Se and Te; Y = F, Cl, Br, EMe and Me) with contributions from CT and compliance constants in noncovalent G⋯E interactions

“…Therefore, it is necessary to select the basis sets and levels for the calculations very carefully. 33 We believe that MP2/6-311+(3df, 3pd) or greater methods, such as MP2/BSS-A, would be necessary if the results are discussed in relation to the observed structural parameters.…”

“…24a, [25][26][27][28]30 The basis sets and levels for the calculations must also be important when the calculated nature is discussed in relation to the observed results. 33 Therefore, higher basis set systems are used for the calculations. QTAIM-DFA and the criteria are explained in the ESI using Schemes S1-S3, Fig.…”