Intermolecular symmetry-adapted perturbation theory study of large organic complexes

Abstract

Binding energies for the complexes of the S12L database by Grimme [Chem. Eur. J. 18, 9955 (2012)] were calculated using intermolecular symmetry-adapted perturbation theory combined with a density-functional theory description of the interacting molecules. The individual interaction energy decompositions revealed no particular change in the stabilisation pattern as compared to smaller dimer systems at equilibrium structures. This demonstrates that, to some extent, the qualitative description of the interaction of small dimer systems may be extrapolated to larger systems, a method that is widely used in force-fields in which the total interaction energy is decomposed into atom-atom contributions. A comparison of the binding energies with accurate experimental reference values from Grimme, the latter including thermodynamic corrections from semiempirical calculations, has shown a fairly good agreement to within the error range of the reference binding energies.

Accurate Treatment of Large Supramolecular Complexes by Double-Hybrid Density Functionals Coupled with Nonlocal van der Waals Corrections

“…Hence, interaction energies at the DLPNO-CCSD(T)/CBS level of theory have been consistently computed for L7 and S12L (Table 2). Hesselmann et al 57 showed that the deformation energies can be important for compounds of S12L and they should be taken into account to provide accurate interaction energy values. Additionally, it was proven that the deformation energies can be overestimated by MP2 due to its overbinding tendency in π-π supramolecular complexes (especially in compounds 3a and 3b).…”

“…56 More recently, Hesselmann et al 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 adapted perturbation theory combined with a density-functional theory description of the interacting molecules. 57 Due to the difference in the methods employed to estimate the reference binding energies in L7…”

Predicting Energetics of Supramolecular Systems Using the XDM Dispersion Model

“…47 The adequate basis-set representation of the intermolecular space has a large impact on the calculation of noncovalent interactions in dispersion-corrected DFT, 47 as well as with other methods. 35 The calculations in ref 23 used PBE-XDM with a combination of basis sets called mixedTZ:cc-pVTZ(seg-opt) for all dimers except 7a, for which TZV was used. Both of the basis sets that form the mixedTZ set lack diffuse primitives.…”

“…62 In sharp contrast, Hesselmann has shown in a recent study that the Symmetry-Adapted Perturbation Theory (SAPT) breakdown of the total energy for the S12L complexes does not have a signature that is particularly different from those of smaller dimers. 35 Then, what is the reason for the results shown in Table 4?…”

“…In a subsequent article, Ambrosetti et al 24 performed Quantum Monte Carlo (QMC) calculations on a subset of these complexes and showed that there were significant differences with some of the experimental results, likely due to inaccuracies in the back-correction caused by the solvation model. 24,35,36 In this work, we explore the ability of the exchange-hole dipole moment (XDM) dispersion model 1,6,37−40 to treat large supramolecular systems by applying it to the S12L dataset. The adequacy of XDM to model these large host−guest systems has recently been put into question by Risthaus and Grimme.…”