Interaction energy electrostatic component

As a consequence of the particular form assumed by the potential Fat large distances (Eq. 79), each coulombic component of the interaction energy (electrostatic, induction, dispersion) varies asymptotically as C R " [13, 23, 61, 63] ... 

Just as with interaction energies, II can be regarded as the sum of several components. These include Ilm due to dispersion interaction, Ilf due to electrostatic interactions between charged surfaces, 11 due to overlapping adsorbed layers of neutral... 

When two or more molecular species involved in a separation are both adsorbed, selectivity effects become important because of interaction between the 2eobte and the adsorbate molecule. These interaction energies include dispersion and short-range repulsion energies (( ) and ( )j ), polarization energy (( )p), and components attributed to electrostatic interactions. 

As the SIBFA approach relies on the use of distributed multipoles and on approximation derived form localized MOs, it is possible to generalize the philosophy to a direct use of electron density. That way, the Gaussian electrostatic model (GEM) [2, 14-16] relies on ab initio-derived fragment electron densities to compute the components of the total interaction energy. It offers the possibility of a continuous electrostatic model going from distributed multipoles to densities and allows a direct inclusion of short-range quantum effects such as overlap and penetration effects in the molecular mechanics energies. 

In summary, rj(r) turns out to be a key index in connecting the electrostatic component of the stacking interaction energy with the hydrogen bonding capacity of cytosine as schematically represented is Figure 27.6. 

It is probable that electrostatic component of resulting interactions on anion-anion distances is registered in such a way. In fact, the calculated value 0.83E practically corresponds to the experimental bond energy values during phosphorylation (first line in table 4) and free energy for ATP in chloroplasts (second line in table 4). 

Requirements for a Mechanistic Model. A significant problem in the use of mechanistic models for the description of the oxide-electrolyte interface is the separation of observed energy of interaction into electrostatic and chemical components. If the separation of energy into these components is completely indeterminate, the apparent mechanistic model may degenerate to an empirical model, being of the correct mathematical form to represent the data, but offering no insight into the chemical nature of the interface. 

Another type of ternary electrolyte system consists of two solvents and one salt, such as methanol-water-NaBr. Vapor-liquid equilibrium of such mixed solvent electrolyte systems has never been studied with a thermodynamic model that takes into account the presence of salts explicitly. However, it should be recognized that the interaction parameters of solvent-salt binary systems are functions of the mixed solvent dielectric constant since the ion-molecular electrostatic interaction energies, gma and gmc, depend on the reciprocal of the dielectric constant of the solvent (Robinson and Stokes, (13)). Pure component parameters, such as gmm and gca, are not functions of dielectric constant. Results of data correlation on vapor-liquid equilibrium of methanol-water-NaBr and methanol-water-LiCl at 298.15°K are shown in Tables 9 and 10. 

An additional electrostatic component to the polymer interaction term is typically unimportant since the counterions strongly screen any Coulomb interactions [92]. Finally, an electrostatic interaction between polymers and counterions Tint occurs if the PE brush is not locally electro-neutral throughout the system, an example is depicted in Fig. 10a. This energy is given by... 

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