Water pair potential

Fellers R S, Leforestier C, Braly L B, Brown M G and Saykally R J 1999 Speotrosoopio determination of the water pair potential Science 284 945-8... 

Groenenboom G, Van der Avoird A, Wormer PES, Mas EM, Bukowski R, Szalewicz K (2000) Water pair potential of near spectroscopic accuracy. II. Vibration-rotation-tunneling levels of the water dimer. J Chem Phys 113 6702—6715... 

For convenience, let us start with the assumption that the water-water pair potential has the general form (more details can be found in chapter 6 of Ben-Naim 1992)... 

Tanaka H, Touhara H, Nakanishi K, Watanabe N. Computer experiment on aqueous solution. IV. Molecular dynamics calculation on the hydration of urea in an infinitely dilute aqueous solution with a new urea-water pair potential. J Chem Phys 1984 80 5170-5186. 

Some of the earliest potentials computed by the SRS variant of SAPT were for Ar-H2 [149] and for He-HF [150,151]. An application of the latter potential in a calculation of differential scattering cross sections [152] and comparison with experiment shows that this potential is very accurate, also in the repulsive region. Some other SAPT results are for Ar-HF [153], Ne-HCN [154], CO2 dimer [155], and for the water dimer [129,156]. The accuracy of the water pair potential was tested [130,131] by a calculation of the various tunnehng splittings caused by hydrogen bond rearrangement processes in the water dimer and comparison with high resolution spectroscopic data [132,133]. Other complexes studied are He-CO [157,158], and Ne-CO [159]. The pair potentials of He-CO and Ne-CO were applied in calculations of the rotationally resolved infrared spectra of these complexes measured in Refs. [160,161]. They were employed [162-165] in theoretical and experimental studies of the state-to-state rotationally inelastic He-CO and Ne-CO collision cross sections and rate constants. It was reaffirmed that both potentials are accurate, especially the one for He-CO. 

Cencek, W., Szalewicz, K., Leforestier, C., van Harrevelt, R., and van der Avoird, A (2008). An accurate analytic representation of the water pair potential, Phys. Chem. Chem. Phys. 10, pp. 4716-4731, doi 10.1039/ b809435g. 

I started to work on the theory of water only in my second year as a post-doctoral fellow at Bell-Labs with Frank Stillinger. For almost two years (1967-1968), I tried to construct a water-water pair potential. Most of the time was spent in determining the parameters of the potential function so that it would fit the experimental molecular properties such as dipole moment, second virial coefficient, and compressibility of ice (see Chapter 2). 

The success of these implementations (discussed in Secs. 2.5 and 2.6) firmed up my conviction that this principle is indeed an essential feature of the water-water interaction in producing the characteristic and outstanding properties of water. The concept of the structure of water is still useful, not as a fundamental principle but as an emergent property of the principle. A qualitative usage of the concept of the structure of water abounds in the literature. In Sec. 2.7,1 shall discuss a possible definition of the structure of water based on the water-water pair potential. Also,... 

Sceats, M. G. Rice, S. A. (1980) The Water-water Pair Potential Near the Hydrogen Bonded Equilibrium Configuration, Journal of Chemical Physics 72, 3236-3247... 

FeUers RS, Leforestier C, Braly LB, Brown MG, SaykaUy RJ (1999) Spectroscopic Determination of the Water Pair Potential. Science 284 945... 

M. G. Sceats and S. A. Rice,/. Chem. Phys., 72,3236 (1980). The Water-Water Pair Potential near the Hydrogen-Bonded Equihbrium Configuration. 

The intennolecular forces between water molecules are strongly non-additive. It is not realistic to expect any pair potential to reproduce the properties of both the water dimer and the larger clusters, let alone liquid water. There has therefore been a great deal of work on developing potential models with explicit pairwise-additive and nonadditive parts [44, 50, 51]. It appears that, when this is done, the energy of the larger clusters and ice has a nonadditive contribution of about 30%. 

In view of the importance of water in chemistry and biology, there have been many attempts to construct simple yet effective intramolecular potentials for water molecules. Water monomers are traditionally left rigid. The early three-site model for water took positive charges on the hydrogens ( h) and a negative charge (qo = on the oxygen, and wrote the pair potential between two... 

Figure 2.3 Site-site interaetion for water 2.6.2 The Effective Pair Potential...

In the case of fluids which consist of simple non-polar particles, such as liquid argon, it is widely believed that Ui is nearly pairwise additive. In other words, the functions for n > 2 are small. Water fails to conform to this simplification, and if we truncate the series after the term, then we have to understand that the potential involved is an effective pair potential which takes into account the higher order-terms. 

The fitting coefficients An for CC14, benzene, and water are listed in Table 8-4. The corresponding effective COM pair-potential, U(r), was obtained by integrating F(r) with the condition that the potential is zero at the outer cutoff ... 

Figure 8-10. Coarse-graining of water, (a) Black COM-COM RDF from EFP-MD, (b) red RDF from CG-MD, (c) orange circles the effective COM pair-force, (d) green polynomial fit of die force matching data, (e) blue the effective COM pair potential...

An alternative to the GB, COSMO, and Poisson electrostatic calculations is to model the solution to the Poisson equation in terms of pair potentials between solute atoms this procedure is based on the physical picture that the solvent screens the intra-solute Coulombic interactions of the solute, except for the critical descreening of one part of the solute from the solvent by another part of this solute. This descreening can be modeled in an average way to a certain level of accuracy by pairwise functions of atomic positions.18, M 65 One can obtain quite accurate solvation energies in this way, and it has recently been shown that this algorithm provides a satisfactory alternative to more expensive explicit-solvent simulations even for the demanding cases of 10-base-pair duplexes of DNA and RNA in water.66... 

In the study of reactivity, Jorgensen and col. have normally used both, the OPLS model and potential functions derived from ab initio calculations. As we have already indicated, when intermolecular pair potentials are applied to the study of a chemical process, the evolution of charges, as well as the Lennard-Jones terms, along the reaction coordinate, has to be considered. For the SN2 reaction in water between chloride anion... 

An interesting combined use of discrete molecular and continuum techniques was demonstrated by Floris et al.181,182 They used the PCM to develop effective pair potentials and then applied these to molecular dynamics simulations of metal ion hydration. Another approach to such systems is to do an ab initio cluster calculation for the first hydration shell, which would typically involve four to eight water molecules, and then to depict the remainder of the solvent as a continuum. This was done by Sanchez Marcos et al. for a group of five cations 183 the continuum model was that developed by Rivail, Rinaldi et al.14,108-112 (Section III.2.ii). Their results are compared in Table 14 with those of Floris et al.,139 who used a similar procedure but PCM-based. In... 

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