Electrons Entrapment and Polarization

The core-level binding energy shifts from that of an isolated atom upon interatomic interaction being involved. 

The exchange integral that is proportional to the single bond energy at equilibrium determines the amount of shift. 

The energy level shift is always positive unless polarization is involved. Atomic undercoordination induced quantum entrapment not only deepens the core level but also enlarges the electroaffinity of a substance. The latter represents the ability of the specimen holding electrons captured from its partner that has lower electronegativity. 

Nonbonding electron polarization not only lowers the work function but also 

Complementing STM/S and PES, ZPS collects coordination-resolved information of bond length, bond energy, binding energy density, atomic cohesive energy and the extent of polarization at sites of defects, monolayer skins, terrace edges, hetero-junction interfaces. 

---

The flexible, polarizable, and segmented 0 H-0 H-bond forms a pair of asymmetric, Coulomb repulsion coupled, H-bridged oscillators, whose relaxation in length and energy and the associated electron entrapment and polarization determines the anomalies of water ice. 

The nature, order, length, and energy of the chemical bond determine the properties of a substance. The formation, dissociation, relaxation, and vibration of the bond and non-bond, and the associated dynamics of electron densihcation, localization, entrapment, and polarization are the key of tuning the property change. The underlying mechanism and the consequences of the surface events are useful in practice ... 

This sequential happening of bond contraction, densification, entrapment, and polarization (bonding-non-bonding electron repulsion and strong correlation) may elaborate the Strong locahzation of Anderson for systems with bond order loss [2]. 

All ZPS profiles show respectively a main valley corresponding to the bulk component. The peak above the valley results from polarization (P) of the otherwise valence electrons by the densely entrapped electrons (T) in the bonding and core orbits. The second peak and the second valley at the bottom edge of the bands result from the joint effects of entrapment and polarization. The locally polarized electrons screen and split the crystal potential and hence split the core band into the P and the T components, which has no effect on the bulk component. The valence LDOS of W(320) atoms exhibits apparently the CN-resolved polarization of W atom at the terrace edge, which is the same to the Au clusters in Fig. 13.3. 

All undercoordinated systems demonstrate the electronic feature of global quantum entrapment and the subjective polarization. Undercoordinated atoms of Au, Ag, Rh, and W show both entrapment and polarization, while the undercoordinated Co and Pt atoms show only entrapment. One neighbor short makes the C atom at the defect site and the ZGNR edge to be completely different from that in the flat graphite surface and in the GNR interior and AGNR edge. 

DFT calculation results in Fig. 20.5 show the polarization of the valence electrons of gold solid clusters and hollow cages and the activation energies for CO oxidation [49]. The lower the effective atomic CN is, the stronger the polarization and the lower the activation energy will be for CO oxidation of the gold catalyst, which is in accordance with observations for Pt catalysts shown in Fig. 20.3. Bond contraction, core electron entrapment, and valence charge polarization happen only to the outermost two atomic layers [49-51]. 

The currently described knowledge about localized charge entrapment and polarization associated with the skin of both the liquid and the solid specimen provides an electronic mechanism for the 4S. According to the BOLS-NEP notation, the small fluidic drop can be viewed as a liquid core covered with a solid-like, densely charged, and elastic sheet with pinned dipoles. The energy density, charge density, polarizability, and the trap depth are bond order dependence. 

As demonstrated, the impact of the often overlooked event of atomic CN imperfection and the associated local quantum entrapment and polarization is indeed profoundly tremendous. The BOLS and NEP notations enable one to view the performance of a defect, surface, a nanosolid, and a solid in amorphous state consistently in a way from the perspective of bond and non-bond formation, dissociation, relaxation, and vibration and the energetic and dynamic process of electron densification, localization, polarization, and redistribution. The following features the progress made in this part ... 

Therefore, the BOLS correlation theory and the XPS measurements enable determination of the interface energetics. The accuracy of estimation is strictly subject to the measurement. Other factors such as materials purity, defect concentration, and testing techniques may lead to the accuracy of the derived E Qi) and Ev(I) values. The developed approach could enhance the power of XPS for extracting more quantitative information regarding the interface properties. The concepts of quantum entrapment and polarization are essential for understanding the bonding and electronic behaviors of hetero-coordinated atoms at the interface region. 

Abstract Hydrogen bonds form a pair of asymmetric, coupled, H-bridged oscillators with ultra short-range interactions, whose asymmetric relaxation and the associated binding electron entrapment and nonbonding electron polarization discriminate water and ice from other usual materials in the structure order and the physical anomalies. 

Cooperative relaxation of the H-bond (0 H-0) in the angle, length, and energy and the associated core electron entrapment and nonbonding electron polarization could be the starting point. 

Thus, a hybridization of the H-O bond contraction [68, 73, 74], local entrapment and polarization [75, 76], and the segmented H-bond relaxation [77] clarify the anomalous behavior of water molecules with fewer than four neighbors. This exercise also reconciled the anomalies of 0-0 expansion, O Is electron densifi-cation and entrapment, surface electron polarization, high-frequency phonon stiffening, and the ice-ltke and hydrophobic nature of such under-coordinated water molecules. Agreement between numerical calculations and experimental observations validated the following hypothesis and predictions ... 

H—0 bond contraction and the associated bonding electron entrapment and the dual processes of polarization create the supersolidity. 

Skin supersolidity slipperizes ice. The H-O contraction, core electron entrapment and dual polarization yield the high-elasticity, self-lubrication, and low-friction of ice and the hydrophobicity of water surface as well, of which the mechanism is the same to that of metal nitride [45, 46] and oxide [47] surfaces. Nanoindentation measurements revealed that the elastic recovery coefficient of TiCrN, GaAlN, and a-Al203 surfaces could reach 100 % under a critical indentation load of friction (<1.0 mN) at which the lone pair breaks with a friction coefficient being the same order to ice (0.1) [42], see Fig. 39.2. Albeit the pressure and the nature of loading pin materials, both show the comparatively low friction coefficients. The involvement of lone pairs makes the nitride and oxide surfaces more elastic and slippery under the critical load. This understanding supplements mechanism for the slippery of ice surface and the hydrophobicity of ultrathin water films as well. 

Bond formation and relaxation and the associated energetics, localization, entrapment, and polarization of electrons mediate the macroscopic performance of substance accordingly... 

---