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SAPT Decomposition

When limited to aromatic molecules with the C2v symmetry point group, the size was initially defined in terms of the angular properties of the ESP profile (see [11] for details). The extension for non-symmetric cases has recently been provided [12]. The size was generalised as an area of positive ESP lying on the boundary of the halogen atom, defined arbitrarily as an isosurface of 0.001 e/bohr [3] electron density [13]. The area has to be refined to have an approximately rounded boundary, since the shape of positive ESP may be quite complicated for nOTi-symmetric molecules [12]. [Pg.5]

The magnitude and size were calculated for all of the halogenated subsystems. Prior to the ESP calculations, all of the molecules were energy minimised. Both the minimisation and the ESP calculations were dmie at the PBEO/aug-cc-pVDZ level with the pseudopotentials on bromine and iodine atoms [14—17]. The calculations were performed in the Gaussian09 program package [18], [Pg.5]


Table 7. Substituent effect (relative energy with respect to the basis set at the MP2/aVDZ level) of the interaction energies and energy components (kcal/mol) for the edge-to-face aromatic interactions (types I and II) by SAPT decomposition... Table 7. Substituent effect (relative energy with respect to the basis set at the MP2/aVDZ level) of the interaction energies and energy components (kcal/mol) for the edge-to-face aromatic interactions (types I and II) by SAPT decomposition...
Table 33.2 SAPT decomposition of ab initio three-body interaction energies (in kcal/mol) for various stationary points on the fitted water trimer potential surface of Ref. [34]. All calculations in trimer-centered [5s3p2dlf/3s2p] basic set of Ref [63] (without bond functions)... Table 33.2 SAPT decomposition of ab initio three-body interaction energies (in kcal/mol) for various stationary points on the fitted water trimer potential surface of Ref. [34]. All calculations in trimer-centered [5s3p2dlf/3s2p] basic set of Ref [63] (without bond functions)...
DF-DFT-SAPT Decomposition of Binding Energy (kcal/mol) for Complexes Formed by CO2 with Various Ligands in Metal-Organic Frameworks... [Pg.337]

Types of intermolecular bonds An excellent overview of hydrogen bonds can be found in the article by Buckingham, Del Bene, and McDowell (Buckingham et al. 2008). In the last few years interest has developed in halogen bonded systems. See Bernal-Uruchurtu et al. (2009) for an introduction and an analysis based on a SAPT decomposition of the interaction energy. [Pg.187]

When the total stabilisation energy depends on both interacting molecules, the same should be true about the components of stabilisation energy. We did not observe any relation between the magnitudes of the o-hole and the polarisation or induction terms of DFT-SAPT decomposition, most likely because of the large effect of the electron donor. [Pg.24]

Decomposition of two- and three-body supermolecular (S-MPPT) interaction energies. The contents of S-MPPT terms is described and the leading SAPT terms are indicated in square brackets. [Pg.669]

In addition to the technical aspects related to the size of molecular systems even more serious problem constitutes the elimination of the basis set dependence of components obtained within different interaction energy decompositions. The performance of various decompositions can be examined by comparison of corresponding results with the most accurate and unquestioned values obtained within rigorously defined perturbational approach with basis sets approaching Hartree-Fock limit. Such accurate results obtained within Symmetry Adapted Perturbation Theory (SAPT) are known for the smallest systems only He2 and H20)2 [6]. [Pg.372]

Cumpaiu.on the accuracy of first order electrostatic and exchange terms obtained within various SCF interaction energy decompositions with corresponding SAPT results for the benchmark test case He..He (R--5.6 au). All interaction energy values are given in nH and corresponding errors are calculated in respect to SAPT results (in parentheses). [Pg.373]

For Inter Molecular Perturbation Theory (IMPT) see Hayes, I. C. Stone, A. J. An intermolecular perturbation theory for the region of moderate overlap, Mol. Phys. 1984, 53, 83-105 papers of this kind, however, contain a large amount of theoretical and mathematical detail and are not transparent to the uninitiated. For Symmetry-Adapted Perturbation Theory (SAPT) see e.g. Bukowski, R. Szalewicz, K. Chabalovski, C. F. Ab initio interaction potentials for simulations of dinitramine solutions in supercritical carbon dioxide with cosolvents, J. Phys. Chem. 1999, A103, 7322-7340, and references therein. The Morokuma decomposition scheme is described in Kitaura, K. Morokuma, K. A new energy decomposition scheme for molecular interactions within the Hartree-Fock approximation, Int. J. Quantum Chem. 1976,10, 325-340. [Pg.116]

In Fig. 9.1, it is possible to find the optimized geometries for six selected clusters, the ab initio structures were obtained at the MP2/AVDZ level [18] and the DFT ones at the B3LYP/AVTZ level. Only two of the three minima found for the 1 1 complex were considered in this work (the missing one differs only in the orientation of the water molecule). As expected the XB interaction leads to a more stable structure than the one stabilized by a XH. The decomposition of the interaction energy using the symmetry adapted perturbation theory (SAPT) for this two structures reveals that they are quite different the electrostatic component of the XB stmcture contributes with 60 % of the interaction energy, the induction with 10 % and dispersion with 30 % whereas for the XH bonded complex it was found that the main contribution to its stability was dispersion with 55 % followed by 31 % of electrostatic and 14 % of induction contribution. This difference between XB and XH interaction is useful to understand why this interaction is not that important in DFT optimized stmctures. The shifts calculated for small clusters are presented in Table 9.1. [Pg.261]

The SAPT method [19] provides an exact decomposition of the total interaction energies into various components of the first and secrnid perturbation order. The DPT version of the SAPT (DFT-SAPT) [20-28] allows for the treatment of extended complexes (up to about 40 atoms) and the total interaction energy is decomposed into polarisation/electrostatic inductirm (E ), dispersion (Ep)... [Pg.5]


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