Theory of intermolecular interactions: The long range terms in the dipole–dipole, monopoles–dipole, and monopoles–bond polarizabilities approximations

Claverie, P.; Rein, Robert

doi:10.1002/qua.560030502

Cited by 54 publications

(11 citation statements)

References 21 publications

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“…corresponds to the major nondirectional contribution to nonbonded interactions. This result is already well known from theories of intermolecular forces [23] and it is known that directional and exchange effects must be added to get anything reasonable. This illustrates the previous comment that the partitioning (26) does not necessarily mean that the correction terms are unimportant.…”

Section: Discussionsupporting

confidence: 55%

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Bond properties from a localized MO-LCAO approach

2009

Int. J. Quantum Chem.

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The problem of theoretically defining bond properties in a simple MO-LCAO method is tackled by partitioning and rearranging the energy expression for a single-determinant wave function built over bond orbitals. The latter are assumed to be formed each by two suitably hybridized MAOS. Orthogonality of the bond orbitals is ensured by a modification of Lowdin's orthogonalization procedure. Theoretical bond energies are defined, discussed, and estimated for a number of bonds. Bond Properties and Simple MO ModelsThe success of large-molecule computations both with ab initio and with allvalence electrons methods is still inducing many researchers to postpone work on the analysis of molecular computations. Among the few exceptions is the work of Gordon and England [l], based on a very deep and far-reaching study of Ruedenberg [2]. There the importance of defining and discussing theoretical bond properties to be compared with those of the classical theory of chemistry is stressed and justified. The importance of transferability, which is deeply connected with the bond concept [2,3], is also given due emphasis. However, some aspects of the general interpretational problem of molecular studies (and in particular the role of the minimal basis MO-LCAO scheme as a model for localization, 0--71 separation, etc.) deserve study along quite different although complementary lines. As an alternative to starting from an all-purpose semiempirical method based on as general a scheme as possible with simplifications essentially justified by numerical success, as is the case with extended Huckel and CNDO-like methods [4], one can imagine that the atomic orbital basis is already "prepared" so as to provide a description of a molecule in terms of bond orbitals, delocalized x systems, and so on. On that basis one may try to define bond quantities in much the same way as is done by a posteriori methods of localization [ 5 , 6 ] .Such a philosophy is interesting, in that it avoids the delicate transferability problem [3] by involving automatically defined bond properties, and that it has the possibility of suggesting when and why bond properties are not exactly trans-

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Section: Discussionsupporting

confidence: 55%

“…Introduction of the latter implies that we are now assuming that the C k i.e., the bond orbitals (5), are eigenvectors of the matrices H::') defined in Equation (23). This involves in principle an approximation which must be compensated by the correction And introduced in Equation (27e).…”

Section: Rabmentioning

confidence: 99%

Bond properties from a localized MO-LCAO approach

2009

Int. J. Quantum Chem.

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“…19 Distributed approaches for both multipoles 14 and polarizabilities 20 have been proposed by Stone. 1 Claverie and Rein 21 have discussed a distributed model for intermolecular interactions involving localized orbitals, and Karlström and co-workers 22 have used a localized orbital approach for constructing intermolecular potentials with the non-empirical molecular orbital method (NEMO). The EFP2-AI dispersion term proposed in the present work involves distributed polarizabilities on the EFP part (which are calculated for localized orbitals) and localized orbital energies and dipole integrals on the AI part of the system.…”

Section: Introductionmentioning

confidence: 99%

The dispersion interaction between quantum mechanics and effective fragment potential molecules

Smith

Ruedenberg²,

Gordon³

et al. 2012

The Journal of Chemical Physics

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A method for calculating the dispersion energy between molecules modeled with the general effective fragment potential (EFP2) method and those modeled using a full quantum mechanics (QM) method, e.g., Hartree-Fock (HF) or second-order perturbation theory, is presented. C 6 dispersion coefficients are calculated for pairs of orbitals using dynamic polarizabilities from the EFP2 portion, and dipole integrals and orbital energies from the QM portion of the system. Dividing by the sixth power of the distance between localized molecular orbital centroids yields the first term in the commonly employed London series expansion. A C 8 term is estimated from the C 6 term to achieve closer agreement with symmetry adapted perturbation theory values. Two damping functions for the dispersion energy are evaluated. By using terms that are already computed during an ordinary HF or EFP2 calculation, the new method enables accurate and extremely rapid evaluation of the dispersioninteraction between EFP2 and QM molecules. The dispersion interaction between quantum mechanics and effective fragment potential molecules Quentin A. Smith, 1 Klaus Ruedenberg, 1 Mark S. Gordon, 1,a) and Lyudmila V. Slipchenko 2,a) A method for calculating the dispersion energy between molecules modeled with the general effective fragment potential (EFP2) method and those modeled using a full quantum mechanics (QM) method, e.g., Hartree-Fock (HF) or second-order perturbation theory, is presented. C 6 dispersion coefficients are calculated for pairs of orbitals using dynamic polarizabilities from the EFP2 portion, and dipole integrals and orbital energies from the QM portion of the system. Dividing by the sixth power of the distance between localized molecular orbital centroids yields the first term in the commonly employed London series expansion. A C 8 term is estimated from the C 6 term to achieve closer agreement with symmetry adapted perturbation theory values. Two damping functions for the dispersion energy are evaluated. By using terms that are already computed during an ordinary HF or EFP2 calculation, the new method enables accurate and extremely rapid evaluation of the dispersion interaction between EFP2 and QM molecules.

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“…The method is of sufficient sensitivity to determine plasma levels in humans after single doses (20 mg) of warfarin (sensitivity of 0.25 pg/ml). (9) to make it more sensitive. This modified method has been successfully employed to study the in uiuo and in uitro availability of commercial warfarin tablets (10).…”

Section: Discussionmentioning

confidence: 99%