THEORY OF INTERMOLECULAR INTERACTIONS

There are two principal methods of calculating the intermolecular interactions the supermolecular method and the perturbational method. Both assume the Born-Oppenheimer approximation. 

---

Rybak, S., Jeziorski,B. and Szalewicz, K. (1991)Many-body symmetry-adapted perturbation theory of intermolecular interactions. FhOandHF dimers,/. Chem. Phys., 95, 6576-6601. 

Here Eh and a are the parameters of a normal Morse potential, and m = mh mi in the framework of the model discussed). Although this combined potential (4.3.26) provides plausible estimates, it can hardly be substantiated in terms of the theory of intermolecular interactions and contains, in addition, only biquadratic anharmonic... 

I. G. Kaplan, Introduction to the Theory of Intermolecular Interactions, Nauka, Moscow, 1982. 

The description of the electronic structure of the complex molecular system given by the system eq. (1.246) is perfectly sufficient when it goes about the hybrid QM/QM methods, when both the parts of the complex system are described by some QM methods. In the case of the hybrid methods in a narrow sense i.e. of the QM/MM methods, further refinements are necessary. The problem is that the description provided by eq. (1.246) suffers from the need to calculate the expectation values in these expressions over the wave function i.e. over the solution of the self-consistency equations eq. (1.246) in the presence of the R-system. This result does not seem to be particularly attractive since the functions < > Y are not known and are not supposed to be calculated in the frame of the MM procedure. Thus the theory must be reformulated in a spirit of the theory of intermolecular interactions [67] and to express necessary quantities in terms of the observable characteristics of free parts of the complex system. 

Chalasinski G, Szczesniak MM (2000) State of the art and challenges of the ab initio theory of intermolecular interactions. Chem Rev 100 4227-4252... 

Kutzelnigg W (1980) The primitive wave function in the theory of intermolecular interactions. J Chem Phys 73 343-359... 

Adams WH (1990) Perturbation theory of intermolecular interactions what is the problem, are there solutions Int J Quantum Chem Sym 24 531-547... 

Jeziorski B, Szalewicz K, Jaszunski M (1979) Pade approximants and the convergence problem in the perturbation theory of intermolecular interactions. Chem Phys Lett 61 391-395... 

The first chapter by Moszyliski presents in a systematic and comprehensive manner the current state-of-the-art theory of intermolecular interactions. Numerous examples illustrate how theoreticians and experimentalists working in tandem may gather valuable quantitative results related to intermolecular interactions, like accurate potential functions, interaction-induced properties, spectra and collisional characteristics or dielectric, refractive or thermodynamic properties of bulk phases. On the other hand the most advanced Symmetry Adapted Perturbation Theory (SAPT) enables validation of more approximate variation-pertubation models which could be applied to the analysis of specific interactions in much larger molecular systems, for example enzyme-drug interactions discussed in Chapter VIII by Berlicki et al. 

AJ. Stone, The theory of intermolecular interactions, Clarendon Press, Oxford 19%. 

Kaplan, I. G. (1982). Introduction To Theory of Intermolecular Interactions. Nauka, Moscow (in Russian). (1985) Theory of Molecular Interactions (transl.). Elsevier Publ., Amsterdam. 

Szalewicz K, Jeziorski B. Symmetry-adapted perturbation theory of intermolecular interactions. In Scheiner S, ed. Molecular Interactions. From van der Waals to Strongly Bound Complexes. New York Wiley, 1997 3 43. 

Mayer and A. Vibok, Chem. Phys. Lett., 136, 115 (1987). SCF Theory of Intermolecular Interactions Without Basis Set Superposition Error. 

The interaction energies of clusters of molecules can be decomposed into pair contributions and pairwise-nonadditive contributions. The emphasis of this chapter is on the latter components. Both the historical and current investigations are reviewed. The physical mechanisms responsible for the existence of the many-body forces are described using symmetry-adapted perturbation theory of intermolecular interactions. The role of nonadditive effects in several specific trimers, including some open-shell trimers, is discussed. These effects are also discussed for the condensed phases of argon and water. 

From the Pauli principle follows that the projected function J4ab o. rather than should be considered as the correct zeroth-order wave function in the perturbation theory of intermolecular interactions. Here J4ab is the usual intermolecular antisymmetrization operator and is (the lowest) eigenfunction of, the sum of... 

Robert Bukowski received his Ph.D. in chemistry in 1996 at the University of Warsaw, Poland, where he worked with Bogumil Jeziorski. In 1997 he joined the group of Krzysztof Szalewicz at the University of Delaware. His research focuses on the theory of intermolecular interactions and its applications in condensed phase simulations. 

The well-established perturbation theory of intermolecular interaction [53 59] can be applied to hydrogen-bonded systems in combination with the frozen molecule approximation, when the interaction is either sufficiently weak [60 62], or when the interaction is treated at a more qualitative level. When the interaction becomes larger, structural relaxations become sizable. Then the more usual approach to treat the hydrogen-bonded complex or cluster as a supermolecule becomes more practical and also more appropriate. However, also in this case, the detailed analysis of the interaction energy is often done with the aid of different variants of energy partitioning techniques [63,64] which closely follow the lines of intermolecular perturbation theory. 

The reader will find the corresponding formulae in the article by A.D. Buckingham, Advan. Chem. Phys. 12 (1967) 107 or by A.J. Sadlej, Introduction to the Theory of Intermolecular Interactions , Lund s Theoretical Chemistry Lecture Notes, Lund, 1990. 

In the perturbation theory of intermolecular interactions at intermediate separations the majority of the physically meaningful effects can be described in second order, provided the coulombic energies (i)-(iii) are supplemented by terms (iv)-(v) arising... 

---