Density functional theory intermolecular forces

In reviewing the performance of density functional theory applied to hydrogen bonded complexes of moderate strength, we repeatedly noted a systematic underestimation of the interaction energies for many types of functionals, usually below 2 kcal/mol. This has been related by some researchers to the inability of modem functionals to describe those contributions to intermolecular binding energies which stem from dispersion forces. Dispersion... 

Y.. Dappe, M.A. Basanta, F. Flores, J. Ortega, Weak chemical interaction and van der Waals forces between graphene layers A combined density functional and intermolecular perturbation theory approach, vol. 74, p. 205434-9, 2006. 

Results. The theory of ternary processes in collision-induced absorption was pioneered by van Kranendonk [402, 400]. He has pointed out the strong cancellations of the contributions arising from the density-dependent part of the pair distribution function (the intermolecular force effect ) and the destructive interference effect of three-body complexes ( cancellation effect ) that leads to a certain feebleness of the theoretical estimates of ternary effects. 

Since the dispersion energy arises from intermolecular correlation of charge fluctuations, it is not accounted for by the usual computational techniques of density functional theory (DPT) which employ the local density and its spatial derivatives. Special techniques are needed if DPT is to be used for investigating problems where intermolecular forces play a significant role. ... 

Outline This review concentrates on work which mainly treats ILs from theoretical considerations and not from an experimental point of view. If calculations play only a supportive role in them, articles may have been neglected on principle. We also refrain from an introduction to methodological aspects and rather refer the reader to good textbooks on the subjects. The review is organized as follows Static QC calculations are discussed in detail in the next section including Hartree-Fock, density functional theory (Sect. 2.2) and correlated (i.e., more sophisticated) methods (Sect. 2.4) as well as semiempirical methods (Sect. 2.1). We start with these kinds of small system calculations because they can be considered as a basis for the other calculations, i.e., an insight into the intermolecular forces is obtained. 

One of the most active areas of research in the statistical mechanics of interfacial systems in recent years has been the problem of freezing. The principal source of progress in this field has been the application of the classical density-functional theories (for a review of the fundamentals in these methods, see, for example, Evans ). For atomic fluids, such apphcations were pioneered by Ramakrishnan and Yussouff and subsequently by Haymet and Oxtoby and others (see, for example, Baret et al. ). Of course, such theories can also be applied to the vapor-liquid interface as well as to problems such as phase transitions in liquid crystals. Density-functional theories for these latter systems have not so far involved use of interaction site models for the intermolecular forces. 

Lately two completely different topics in the field of intermolecular forces have drawn attention and are now actively being studied. In the first place there is the possible application of density functional theory (DFT) to van der Waals molecules. The second topic concerns van der Waals molecules of which the electronic state of one or more of the monomers is spatially degenerate. 

Volkov, A., Koritsanszky, T, and Coppens, P. [2004]. Combination of the exact potential and multipole methods [EP/MM] for evaluation of intermolecular electrostatic interaction enei ies with pseudoatom representation of molecular electron densities, Chem. Phys. Lett 391, pp. 170-175, dol 10.1016/j.cplett.2004.04.097. von Lilienfeld, 0. A., Tavernelli, 1., Rothlisberger, U., and Sebastian , D. [2004]. Optimization of effective atom centered potentials for London dispersion forces in density functional theory, Phys. Rev. Lett 93,15, p. 153004. 

Density functional theory (DPT) calculations [18] suggest the tangential pulling force Ft as a solid/liquid adhesion originated in long-range solid/liquid intermolecular attraction... 

The mean field density functional theory (DFT) approach was primarily developed by Evans and co-workers [67,68] for studying the interactions of fluids in pores at the molecular level. Recently, DFT methods have been developed specifically with the objective of the estimation of PSD of carbon-based as well as other types of microporous materials. This technique was first proposed by Seaton et al. [16], who used the local-DFT approximation. Later, the theory was modified by Lastoskie et al. [17,18] to incorporate the smoothed or nonlocal DFT approach. The rigorous statistical mechanics basis behind the DFT model has been recently reviewed by Gubbins [34]. Some sahent features of the theory are discussed later in this subsection. The DFT method initially proceeds by estimating the properties of a fluid directly from intermolecular forces such as that between sorbate-sorbent and sorbate-sorbate molecules. The interactions are divided into a short-ranged repulsive part and a long-ranged attractive part, which are both determined separately. 

Some of the contributions address the calculation of intermolecular forces at a fimdamental level, while the majority are concerned with appHcations, ranging from water clusters, through smfaces, to crystal structures. Sza-lewicz, Patkowski and Jeziorski provide a timely review of how perturbation theory can be used to address intermolecular forces in a systematic way. In particular, they describe a new version of symmetry-adapted perturbation theory, which is based on a density functional theory description of the monomers. The interpretation of bonding patterns for both intra- and intermolecular interactions is addressed in Popelier s review, which focuses on quantum chemical topology. He suggests a novel perspective for treating several of the most important contributions to intermolecular forces, and explains how these ideas are related to quantum delocalization. 

Antony, J., Grimme, S. (2006). Density functional theory including dispersion corrections for intermolecular interactions in a large benchmark set of biologically relevant molecules. Physical Chemistry Chemical Physics, 8, 5287. Arnautova, Y. A., Scheraga, H. A. (2008). Use of decoys to optimize an all-atom force field including hydration. Biophysical Journal, 95, 2434. 

Misquitta, A. J., 8c Szalewicz, K. (2005). Symmetry-adapted perturbation-theory calculations of intermolecular forces employing density-functional description of monomers. Journal of Chemical Physics, 122, 214109. 

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