Charge transfer calculations

Thus, the number of peaks is not merely a function of AEf, as in the reversible case. As an example, the CV curves corresponding to a two-electron non-reversible charge transfer calculated for A Ef = 0 V and Xplane, (=1) and different values of Kpiane2 have been plotted in Fig. 6.4. From these curves, it is clear that the morphology of the voltammograms evolves from a single pair of peaks for the case in which Kplane 1 = Xplane 2 to the appearance of a second pair of peaks which are... 

Fig. 8. Relative velocity dependence of integral cross sections calculated for Na + O collisions for the indicated exit channels. The solid curve is the charge transfer cross section calculated using a multichannel Landau-Zener formalism (see text). The dashed curve is the two-state Landau-Zener cross section. Charge transfer calculations by van den Bos are indicated by triangles. Full circles and squares are the respective excitation channels as determined using the multichannel Landau-Zener model.

The charge transfer term arises from the transfer of charge (i.e. electrons) from occupied molecular orbitals on one molecule to unoccupied orbitals on the other molecule. This contribution is calculated as the difference between the energy of the supermolecule XY when this charge transfer is specifically allowed to occur, and an analogous calculation in which it is not. 

Quinolizinium iodide, 3,4-dihydro-dehydrogenation, 2, 547 Quinolizinium iodide, 2-methylthio-synthesis, 2, 544 Quinolizinium ions, 2, 525-578 aza analogues, 2, 525-578 charge transfer bands, 2, 527 MO calculations, 2, 527 nomenclature, 2, 526 structure, 2, 3 UV spectra, 2, 19, 526-527 Quinolizinium ions, hydroxydihydro-reactions, 2, 549... 

Figure 2. The average number of electron charges transferred from Zn atoms to Cu atoms in fee disordered alloys. The solid dots are calculated with the LSMS. The open circles are obtained using the CPA-LSMS. The squares are obtained using the SCF-KKR-CPA.

Second, using the fully relativistic version of the TB-LMTO-CPA method within the atomic sphere approximation (ASA) we have calculated the total energies for random alloys AiBi i at five concentrations, x — 0,0.25,0.5,0.75 and 1, and using the CW method modified for disordered alloys we have determined five interaction parameters Eq, D,V,T, and Q as before (superscript RA). Finally, the electronic structure of random alloys calculated by the TB-LMTO-CPA method served as an input of the GPM from which the pair interactions v(c) (superscript GPM) were determined. In order to eliminate the charge transfer effects in these calculations, the atomic radii were adjusted in such a way that atoms were charge neutral while preserving the total volume of the alloy. The quantity (c) used for comparisons is a sum of properly... 

We conclude that more work is need<. In particular it would be useful to repeat the TB-LMTO-CPA calculations using also other methods for description of charge transfer effects, e.g., the so-called correlated CPA, or the screened-impurity modeP. One may also cisk if a full treatment of relativistic effects is necessary. The answer is positive , at least for some alloys (Ni-Pt) that contain heavy elements. 

Fig.l. Results for the system Zn/Cu. Calculated charge transfer from (shown as positive) or towards (shown as negative) the impurity site obtained according to eqn.(2) of text (dashed line) as a function of the potential shift applied on the impurity potential. The variation given by eqn.l is indicated by the solid line while the dotted line indicates the solution which includes corrections due to the redistribution of the impurity charge. 

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