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Water dimer analysis

Stevens WJ, Fink WH (1987) Frozen fragment reduced variational space analysis of hydrogen bonding interactions. Application to water dimer. Chem Phys Lett 139 15... [Pg.169]

TABLE 10. Morokuma-Kitaura component analysis of the SCF interaction energy of the water dimer ... [Pg.1054]

The quantities in Table II unambiguously show that for the water dimer the terms follow similar regulations as found for the water monomer. The problem, however, is that the analysis of the water dimer does not provide information on the monomers behavior donor or acceptor, when using the canonical represent-tation. Let us consider smaller or larger basis sets the results do not provide any characteristic feature on the monomers although (due to a sub-symmetric relationship of the monomers in the dimer) the electron structures of the monomers are different. [Pg.341]

Following the analysis of the characteristic features determined for the proton donor and acceptor molecules in a linear water dimer, we performed the same study for some water hexamer clusters. The structures considered are representative of those published in a previous paper [18]. [Pg.342]

Studying the ESPT of hydroxy aromatic sulfonates, Huppert and co-workers [40-44] suggested an alternative model based on the geminate proton-anion recombination, governed by diffusive motion. The analysis was carried out by using Debye-Smoluchowskii-type diffusion equations. Their ESPT studies in water-methanol mixtures showed that solvent effects in the dissociation rate coefficient are equal to the effects in the dissociation equilibrium constant [45], 4-Hydroxy-1-naphthalenesulphonate in a water-propanol mixture as the solvent system has been found to behave somewhat differently than water-methanol or water-ethanol media, with a possible role of a water dimer [46,47],... [Pg.580]

Hydrogen fluoride dimer, like with the water dimer, is one of the most frequently studied complexes. Both extensive theoretical and experimental data are available for analysis. The PES of the hydrogen fluoride dimer (see Figs. 15 and 16), if compared with that of water, is simpler two stationary points exist the quasi-linear" structure (see Fig. 15) and the cyclic structure (see Fig. 16). [Pg.339]

Thole, B.T. and Duijnen P.Th. van, The direct reaction field hamiltonian analysis of the dispersion term and application to the water dimer. Chem.Phys. (1982) 71 211-220. [Pg.95]

Singh UC, Kollman PA (1985) A water dimer potential based on ab-initio calculations using Morokuma component analysis. J Chem Phys 83 4033-4040... [Pg.512]

The HF dimer is predicted to nearly perfect accuracy by this simple electrostatic prescription. The prediction deteriorates somewhat for the water dimer, but falls apart entirely for (NH3)2- The poor performance in the latter case is not surprising since the surface is extremely flat, even with the most precise full calculations available. Excellent agreement is obtained for the mixed dimers in the last two rows of Table 3. A later study, which carried the analysis one step further to R 6, indicated the series is not yet entirely stable, and changes of several degrees are to be expected at this level [39]. [Pg.576]

The former analysis may perhaps be best understood by way of an example. Let us consider first the water dimer in its most stable orientation. The geometries were optimized with a modest basis set at the SCF level, but the results are illustrative nonetheless, and more accurate calculations would not influence the example in any important respect. Figure 1.2a illustrates the geometry of the monomer and the directions of the three principal moments of inertia the dimer is depicted in Fig. 1.2b. Table 1.2 reports the total mass of each species in the first row, followed by the translational energy at 25° C, 3/2 RT. Since there are two reactants and only one product, and all with the same translational energy, for the... [Pg.19]

Reed, A. E., and Weinhold, F., Natural bond orbital analysis of near Hartree-Fock water dimer, J. Chem. Rhys. 78,4066-4073 (1983). [Pg.50]

Jensen, J. H. and Gordon, M. S., Ab initio localized charge distributions Theory and a detailed analysis of the water dimer-hydrogen bond, J. Rhys. Chem. 99, 8091-8097 (1995). [Pg.50]

Recent ab initio calculations have attempted to probe the fundamental source of the reversal of H/D preference in ionic as compared to neutral systems, using water as a test base. A harmonic analysis of the potential energy surface of the water dimer, computed with a 6-31G basis set, indicates that the preference for D in the bridging site can be explained in a manner similar to that described earlier for HF - HF. The frequency of the bending motion of the bridging atom is sensitive to its mass this effect leads to a lower vibrational energy of some 0.2 kcal/mol when the heavier D undergoes this motion. The computations indicated that electron correlation has little effect upon this conclusion, even its quantitative aspects. While the treatment was purely harmonic in nature, other calculations have indicated that anharmonicity effects yield very little distinction between one isotopomer and the next. [Pg.120]

Indeed, low intensities are expected in any H-bonded complex for which is constituted primarily of the intermolecular stretch. What lends intensity to this band in a complex like (HF)2 is the contribution of bending motions that change the dipole moment vector direction, and internal HF stretches that alter the subunit s moment. For example, Swanton et al. had determined in their analysis of the water dimer that 70% of the intensity can be attributed to internal motions within the two water subunits. [Pg.152]

Most recently, Glendening and Streitwicser have decomposed the interaction energy of the water dimer using natural bond orbitals. Their natural energy decomposition analysis (NEDA) combines the normal electrostatic and exchange energies into a single ES term,... [Pg.222]

J. H. Jensen and M. S. Gordon, Initio Localized Charge Distributions Theory and Detailed Analysis of the Water Dimer-Hydrogen Bond, J. Phys. Chem. 99, 8091-8107 1995. [Pg.223]


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Water analysis

Water dimer

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