Kitaura-Morokuma analysis

The natural energy decomposition analysis (the keyword is NEDA) of Glendening and Streitwieser provides a more comprehensive picture of the various energy components contributing to intermolecular interactions. The NEDA decomposition mimics in some ways the older Kitaura-Morokuma analysis, but it avoids the use of non-orthogonal (and exclusion principle-violating) wavefiinctions for the two monomers, with the attendant interpretational ambiguities. 

TABLE 10. Morokuma-Kitaura component analysis of the SCF interaction energy of the water dimer ... 

Different Contributions to Hydrogen Bonding Energy According to Analysis by Kitaura-Morokuma Method... 

To overcome these drawbacks, the scheme was modified by Morokuma and Kitaura and is the popular EDA tool currently used. Similar to the Morokuma analysis in KM scheme, the energies of isolated monomers are first evaluated and the energy of the unperturbed complex is expressed as the sum of their energies ... 

Morokuma, K. Kitaura, K. Energy Decomposition Analysis of Molecular Interactions in Chemical Applications of Atomic and Molecular Electrostatic Potentials, Politzer, P Ed. Plenum New York, 1981, pp. 215-242. 

Table 1.6 Comparison between Morokuma-Kitaura and natural energy decomposition analysis (NEDA) " . All values in kcal/mol, calculated with 4-3IG basis set. 

Decomposition of interaction energies is desired for qualitative chemical analyses of complicated multi-valent interactions in supramolecular aggregates but such a decomposition cannot be uniquely defined within fundamental physical theory. A popular semi-quantitative decomposition method with nice formal features to be mentioned in this context is Weinhold s natural bond orbital (NBO) approach to intermolecular interactions [232, 233]. Comparable is the recently proposed energy decomposition analysis by Mo, Gao and Peyerimhoff [234, 235] which is based on a block-localized wave function. Other energy decomposition schemes proposed are the energy decomposition analysis (EDA) by Kitaura and Morokuma [236] and a similar scheme by Ziegler and Rauk [237]. 

Morokuma K, Kitaura K. Energy decomposition analysis of molecular interactions. In Politzer P, Truhlar DG, eds. Chemical Applications of Atomic and Molecular Electrostatic Potentials. New York Plenum, 1981 215-242. 

The first and very popular energy decomposition scheme that is used to decompose the total INT into various contributing factors was developed by Kitaura and Moroknma in the late 1970s. This method was mainly developed to decompose the INT of hydrogen-bonded systans within the Hartree-Fock approximation. Since then, it has also been successfully applied to donor-acceptor pairs, % and a interactions in transition metal complex, and decomposition of electron density. A broad outline of the key steps involved in the analysis of various components of the INT is provided in the following section. Before we proceed to the KM analysis in detail, it is important to look at the initial decomposition scheme developed by Morokuma. We start the discussion by taking a dimer AB into consideration. 

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