A Cost Effective Scheme for the Highly Accurate Description of Intermolecular Binding in Large Complexes

Abstract

There has been a growing interest in quantitative predictions of the intermolecular binding energy of large complexes. One of the most important quantum chemical techniques capable of such predictions is the domain-based local pair natural orbital (DLPNO) scheme for the coupled cluster theory with singles, doubles, and iterative triples [CCSD(T)], whose results are extrapolated to the complete basis set (CBS) limit. Here, the DLPNO-based focal-point method is devised with the aim of obtaining CBS-extrapolated values that are very close to their canonical CCSD(T)/CBS counterparts, and thus may serve for routinely checking a performance of less expensive computational methods, for example, those based on the density-functional theory (DFT). The efficacy of this method is demonstrated for several sets of noncovalent complexes with varying amounts of the electrostatics, induction, and dispersion contributions to binding (as revealed by accurate DFT-based symmetry-adapted perturbation theory (SAPT) calculations). It is shown that when applied to dimeric models of poly(3-hydroxybutyrate) chains in its two polymorphic forms, the DLPNO-CCSD(T) and DFT-SAPT computational schemes agree to within about 2 kJ/mol of an absolute value of the interaction energy. These computational schemes thus should be useful for a reliable description of factors leading to the enthalpic stabilization of extended systems.

Reliable Dimerization Energies for Modeling of Supramolecular Junctions

“…Table 1 shows the dimerization energy values predicted by the aforementioned theoretical methods for complexes whose size does not exceed 32 atoms, while Table S1 specifies the sources of the geometry of these complexes. These systems were included mainly for checking the current computational methodology, as their canonical CCSD(T)/CBS Δ E values were estimated in previous investigations (see references [ 42 , 43 , 44 ] and the works cited therein, along with the footnotes to Table 1 ). Importantly, the Δ E data span a large interval from ca.…”

“…The CP DLPNO-CCSD(T)/CBS interaction energy was estimated using the focal-point procedure (see reference [ 43 ]) described by Equation (2), where the notation is as in Equation (1), and the right arrow indicates an application of the two-point extrapolation formula from reference [ 71 ]: …”

On the Intermolecular Interactions in Thiophene-Cored Single-Stacking Junctions

“…In short, numerous starting orientations were prepared, and minima of the PES were sought by the B97-D/def2-TZVPP approach (it should be noted that this method was recently used to search the PES of numerous dimers of heterocycles [14]). The resulting minima were ranked by the DLPNO-CCSD(T)/CBS estimation of the ∆E using the focal point procedure developed most recently [15]. As detailed in reference [15], this procedure was shown to provide ∆E-values accurate to within about 2 kJ/mol for some challenging cases from the L7 set [16] and for other complex systems.…”

The Unconventional Noncovalent Interactions Control: Crystallographic and Theoretical Analyses of the Crystalline Structure of 1,1′‐(1‐Chloro‐4‐methoxyphenyl)dibenzene as a Case Study

“…However, experimental characterization is challenging due to the transient and weak nature of the interactions. Fortunately, computational chemistry methods are proving invaluable in assessing their nature and energetics.. [34][35][36][37][38] In this study, the crystalline structure of 1,1'-(1-chloro-4methoxyphenyl)dibenzene, a covalent dimer derived from 1chloro-4-methoxybenzene, [39][40][41] was selected as a representative case, to illustrate the importance of these interactions in crystal packing. It is worth remarking that our goal here is to unravel the unconventional interactions rather than present the mentioned structure.…”

“…Fortunately, computational chemistry methods are proving invaluable in assessing their nature and energetics. [34–38] …”