Isopotential curves

Fig. U (o) Isopotential curves for the adsorption of He on the (100) face of solid Xe. The interval between the isopotential lines is 1-24 x 10 J. [b) Isopotential curves for the adsorption of He on the (III) face of solid Xe. The interval between the isopotential lines is 1-66 x 10 J. (After...

Figure 13. (a) Isopotential curves for the adsorption of one He atom on the (1 00) face of solid Xe. Intervals between curves are 1.24 x 10 22 J (after Ricca, 1967). (b) Potential energy of an adsorbed He atom moving along line AB. 

Curves for the same energy level, or isopotential curves, represent an interaction map between the positive charge and the inhibitor molecule, and are displayed on a Benson-plotter. 

Figure 3. Electrostatic potential map for the two bare defects and identification of the position of the atoms of the dissociated H2 molecule (H atoms in the Tfi configuration are in dark grey). The sections are in a vertical plane through the H atoms. Consecutive isopotential lines differ by 0.02 a.u. (0.54 V) continuous, dashed and dot-dashed curves refer to positive, negative, arid zero potential, respectively. Lines corresponding to absolute values larger than 0.3 a.u. are riot plotted.

Figure 36 On the left Structure of ice XI On the right Electrostatic potential at the (001) surface of ice XL Consecutive isodensity lines differ by 0.01 a.u. continuous, dashed, and dot-dashed curves correspond to positive, negative, and zero potential, respectively. Isopotential lines corresponding to potential values larger than 0.2 a.u. in module are not plotted.

Let us briefly review which of the listed values and in what manner can be determined. It is possible to calculate the distribution of complex species in the solution, that is, bulk concentrations or activities, by means of the methods discussed in Chapter 1. Besides, the composition of solutions can be changed so that Eqs. (7.8)-(7.10) would become simpler. For example, one can use a series of solutions with constant concentration of free ligand for which i In l = 0- In the series of isopotential solutions (see Section 2.1), the condition dlna = 0 holds. By differentiation of the electrocapillary curve with respect to E for a solution of constant composition, one can obtain the value of the charge density e and use Eq. (7.6) for the calculation of total adsorptions Fj x nd Flx. Thus, electrocapillary measurements, as well as a number of other methods (radioactive indicator, surface stress, piezoelectric, extensometer methods), give information only about the total amounts of adsorbed metal and ligand. Consequently, for further solution of the problem posed, some model images are necessary. 

---