Electrostatic charge defined

MM+ calculations do not usually have an electrostatic charge-charge interaction nor define a set of atomic charges for atoms. 

The fitting of electronegativities and hardnesses is done independently of each other with the help of a reformulation of the fluctuating charge model in terms of a linear response model [117, 120, 210], In the presence of an external potential the electrostatic energy defined in Eq. (9-35) is ... 

The acidity (as defined by the pK NB a strong acid has a low p.K) of a molecule is strongly influenced by its electrostatic charge distribution, and this is not surprising since the partial negative charge on the O atom in... 

High immobilization density may be defined as the case where there is a high likelihood of significant interaction between neighbouring oligonucleotides (e.g. mean centre-to-centre strand separation distances of less than 50 A) and tends to provide the best results in terms of selectivity. Hybridization may be considered as a process that injects extra electrostatic charge... 

Consider a fully developed dilute gas-solid flow in a vertical pipe in which solid particles carry significant electrostatic charges. The particle charges vary radially. It is assumed that (a) the flow and the electrostatic field are axisymmetric and (b) the radial charge distribution C(r), defined as q(r)af(r), is known. Derive an expression for the radial volume fraction distribution of the particles. 

The structure of yint depends, in general, on the nature of the solute-solvent interaction considered by the solvation model. As already noted in the contribution by Tomasi, a good solvation model must describe in a balanced way all the four fundamental components of the solute-solvent interaction electrostatic, dispersion, repulsion, charge transfer. However, we limit our exposition to the electrostatic components, this being components of central relevance, also for historical reason, for the development of QM continuum models. This is not a severe limitation. As a matter of fact, the QM problem associated with the solute-solvent electrostatic component defines a general framework in which all the other solute-solvent interaction components may be easily collocated, without altering the nature of the QM problem [5],... 

A variant of [3.6.36] applies to the case where, say positive, charges on the surface act as the sites where specific adsorption of anions may occur, i.e. when the specific adsorption is of the second kind. Then ion pairs are formed, held together by electrostatic and non-electrostatic interactions. Defining 0 as the fraction of [Pg.309]

Note that another, nontrivial advantage of the atomic charge defined by Eq. [50] is that they are given in terms of a well-defined quantum mechanical observable. This is desirable and avoids the need to parameterize the charges by fitting some other observable, such as the electrostatic potential at a set of external points. 

The relaxation time t, in connection with electrostatic charge /discharge processes is defined as ... 

The next question that arises is, having included the electrostatic potential in the set of components, how do we write a total concentration for this component For the other components, hydrogen ion and surface hydroxyl groups, the total concentration is determined simply by how much acid or base, or how much surface we have added to the system. In the case of the electrostatic component, we can use the independent electrostatic charge-potential relationship to define a total concentration or charge for the surface—in the case of the constant-capacitance model... 

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