Crystal charge

Figure 4. Calculated HAB values as a function of Fe -Fe separation, based on the structural model given in Figure 1 and the diabatic wavefunctions I/a and f/B. Curves 1 and 2 are based on separate models in which the inner-shell ligands are represented, respectively, by a point charge crystal field model [Fe(H20)62 -Fe(HsO)63 ] and by explicit quantum mechanical inclusion of their valence electrons [Fe(HgO)s2 -Fe(H20)s3+] (as defined by the dashed rectangle in Figure 1). The corresponding values of Kei, the electronic transmission factor, are displayed for various Fe-Fe separations of interest.

Schofield RK, Samson HR (1954) Flocculation of kaolinite due to the attraction of opposite charged crystal faces. Discuss Faraday Soc 18 135-145 Schofield RK, Samson HR (1953) The defiocculation of kaolinite suspensions and the accompanying change-over from positive to negative chloride adsorption. Clay Miner BuU 2 45-51 Schulten HR (2001) Models of humic structures association of humic acids and organic matter in soils and water. In Qapp CE et al. Humic substances and chemical contaminants. Soil Science Society of America, Madison, Wl, pp 73-88... [Pg.375]

The Accelerated Convergence Method and the Electrostatic Potential in a Point-Charge Crystal... [Pg.196]

The electrostatic properties of a point-charge crystal are given by the direct space sum... [Pg.196]

The electrostatic potential in a crystal of spherical atoms or ions is therefore the sum of the electrostatic potential of a point-charge crystal and a penetration correction. Only atoms for which the product of RuCj is small contribute to the... [Pg.198]

For the unit-point-charge crystal, the absolute value of the electrostatic energy is equal to the potential at the nuclear position. This potential will be equal for both ions in the alkali halide structure, as their positions are equivalent that is,... [Pg.200]

Schofield, R. K., and H. R. Samson. 1954. Flocculation of kaolinite due to the attraction of oppositely charged crystal faces. Discuss. Faraday Soc. 18 135-145. [Pg.546]

Fig. 3. Schematic correlation diagram showing excitation energies for Co " in various environments. Left to right free ion ion in point charge crystal field energies from cluster calculation in bulk site energies from cluster calculations in surface site experimental bulk excitation energies. The inset shows schematic one-electron 3d energy levels in bulk and surface sites. Adapted from ref. 91.

Panicle size, concentration, and chemical composition arc usually the aerosol properties of most interest. Also imponant in certain applications arc particle charge, crystal stmeture and optical properties. In Industry, particles are collected to recover a desirable product or reduce emissions and occiiputional exposures. The efficiency of filters, scrubbers and other such devices depends primarily on particle size. As shown in Chapter a minimum is often found when the efficiency of particle rentoval is plotted a.s a function of particle size. The efficiency minimum or window" occurs in the particle size range near a few tenths of a micron for reasons that differ depending on the mechani.sms of particle collection. A similar efficiency mintniLini is observed for particle deposition in the lung as a function of particle size. The explanations for the efficiency minima in the lung and certain types of filters are similar. [Pg.2]

Rather little is known about the d—d spectra of bromocuprates(II). Ludi and Feitkneckt (1963) reported the powder reflectance spectrum of CuBr2 and observed a single broad band around 12 kK. Day (1964) gave a point charge crystal field treatment of CuBr2, and Day and Jorgensen... [Pg.76]

Day, P. (1964) Point charge crystal field calculations for cupric halides. Proc. Chem. Soc. (London) 18. [Pg.105]

Fig. 3. Schematic depiction of the octahedral point charge crystal field model. In the free ion, the set of five d orbitals is degenerate. When the ion is placed in a solid and bonds to six nearest neighbor ligands arranged in an octahedral geometry, the d orbitals split into eg (dz, dz2 y0 and t2g (dxy, dxy,dyz) subsets separated by an energy lODq...

Schofield RK, Samson HR (1954) Flocculation of Kaolinite Due to Attraction of Oppositely Charged Crystal Faces. J Discuss Faraday Soc No IB pp 134-45... [Pg.36]

Isomorphic substitutions are possible in the case of ions of approximate radii. For example Sr with the radius 113 pm easily substitutes Ca (r=99 pm) in all clinker phases. The situation is more complicated if the substitution is regarding ions of different charge. Crystal as a whole must be electrically neutral. The different cases are then possible group substitution, e g. [Ca, Si" 2A1 +. Aluminium... [Pg.76]

Free metal ion Metal ion plus ligands Splitting due to (negative point charges) crystal field... [Pg.969]

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