Localized electron summary

In summary, electrons can be localized within an atomic boundary in a closed-shell interaction. They can also be separately localized within the inner or valence shells, but not to bonded regions which cross interatomic surfaces, nor, in general, to non-bonded regions which occupy only a portion of a valence shell, to yield the Lewis model of the localized electron pair. 

Localized Electron Model sp3 Hybridization sp Hybridization sp Hybridization dsp Hybridization d sp Hybridization The Localized Electron Model A Summary... 

In summary, (a>) is characteristic of strongly localized electrons (t 10 s) for samples E-G far from the IMT. For samples A-D near the IMT, a small fraction of the carriers become macroscopically delocalized (t > --- 10 s) while the majority of carriers are still strongly localized (t 10 s). The difference between metallic sample A and insulating sample D is that the free carriers freeze out in sample D at low T. This behavior is characteristic of percolating systems. Unlike the usual percolating systems, the percolation for doped polymers can be temperature-dependent. The dielectric response of oriented materials clearly points out the importance of dimensionality in the electronic behavior. 

Since the pioneering cluster calculation on the KNiFs solid of Shulman and Sugano [6] there has been a wide variety of proposals of procedures to handle relatively localized electronic states of a solid with a molecule-like Hamiltonian that includes the relevant solid host effects, depending on the type of solids and on methodological flavors (Green s functions, wavefunctions, density functional, etc.). A recent summary of practical methods can be found in Huang and Carter [7]. Here we describe our choice of embedded-cluster method, particularly useful in ionic materials. 

In summary, all the experiments expressly selected to check the theoretical description provided fairly clear evidence in favour of both the basic electronic model proposed for the BMPC photoisomerization (involving a TICT-like state) and the essential characteristics of the intramolecular S and S, potential surfaces as derived from CS INDO Cl calculations. Now, combining the results of the present investigation with those of previous studies [24,25] we are in a position to fix the following points about the mechanism and dynamics of BMPC excited-state relaxation l)photoexcitation (So-Si)of the stable (trans) form results in the formation of the 3-4 cis planar isomer, as well as recovery of the trans one, through a perpendicular CT-like S] minimum of intramolecular origin, 2) a small intramolecular barrier (1.-1.2 kcal mol ) is interposed between the secondary trans and the absolute perp minima, 3) the thermal back 3-4 cis trans isomerization requires travelling over a substantial intramolecular barrier (=18 kcal moM) at the perp conformation, 4) solvent polarity effects come into play primarily around the perp conformation, due to localization of the... 

This initial attack of the ozone molecule leads first to the formation of ortho- and para-hydroxylated by-products. These hydroxylated compounds are highly susceptible to further ozonation. The compounds lead to the formation of quinoid and, due to the opening of the aromatic cycle, to the formation of aliphatic products with carbonyl and carboxyl functions. The nucleophilic reaction is found locally on molecular sites showing an electronic deficit and, more frequently, on carbons carrying electron acceptor groups. In summary, the molecular ozone reactions are extremely selective and limited to unsaturated aromatic and aliphatic compounds as well as to specific functional groups. 

Summary. We study how the single-electron transport in clean Andreev wires is affected by a weak disorder introduced by impurity scattering. The transport has two contributions, one is the Andreev diffusion inversely proportional to the mean free path i and the other is the drift along the transverse modes that increases with increasing . This behavior leads to a peculiar re-entrant localization as a function of the mean free path. 

After a brief summary of the molecular and MO-communication systems and their entropy/information descriptors in OCT (Section 2) the mutually decoupled, localized chemical bonds in simple hydrides will be qualitatively examined in Section 3, in order to establish the input probability requirements, which properly account for the nonbonding status of the lone-pair electrons and the mutually decoupled (noncommunicating, closed) character of these localized a bonds. It will be argued that each such subsystem defines the separate (externally closed) communication channel, which requires the individual, unity-normalized probability distribution of the input signal. This calls for the variable-input revision of the original and fixed-input formulation of OCT, which will be presented in Section 4. This extension will be shown to be capable of the continuous description of the orbital(s) decoupling limit, when AO subspace does not mix with (exhibit no communications with) the remaining basis functions. 

Since the magnitude of the atomic moment will be shown to depend sharply upon the collective versus localized character of the electrons, magnetic as well as electric data will be found (see Chapter III) to support these tentative conclusions. Therefore, a brief summary is given of the formal results and of the assumptions made for the collective (MO) versus localized (HL) descriptions of electrons in crystals. 

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