2.2 Core Band Energy Dispersion
29
lines for the spin-resolved energy levels, such as the 1s, 2p 1/2 , and 2p 3/2 of Cu.
Electronic occupation of the core bands often approximates the Gaussian or the
Lorentz type functions in decomposing the spectral peaks.
2.3 BOLS-NEP-LBA Notion
2.3.1 Local Hamiltonian Perturbation
Atomic CN is the primary variable that determines the CLS for undercoordinated
systems. Any change of the CN will relax the bond in length and energy accordingly,
which perturbs the V cryst (r). Possible factors of perturbation include:
(1) Undercoordination induced bond contraction, charge densification, localization,
entrapment, and polarization.
(2) Hetero-coordination induced bond nature alteration, bond relaxation, entrapment, or polarization.
(3) Radiation induced ionization associated with the “initial-final states” relaxation
during experiment.
(4) External bias caused charge accumulation of the tested specimen.
(5) Mechanical or thermal field induced bond relaxation in length and energy.
The zeroth approximation of the interatomic potential dictates the CLS.
Figure 2.2a illustrates bond length and energy (d, E) relaxation along the modulation function f (x) under a certain stimulus x such as the atomic CN, mechanical,
0.6
0.8
1.0
1.2
-1.5
-1.0
-0.5
0.0
0.5
C
-m
i
(E
i
/E
b
)
f(x)
C i
(a)
(b)
Fig. 2.2 Potentials of a dimer bond relaxing under external stimulus x. a Valley of the pairing
potential u(r, E) corresponds to bond length and energy (d, E b ) that relax along the modulation
function f (x) under stimulus x (x can be pressure, temperature or coordination environment, etc.).
b Bond order loss shortens and strengthens bonds between undercoordinated atoms at the bonding
network terminals such as sites of defects and skins of nanocrystals, which cause local densification
and entrapment of the bonding electrons, and polarization of nonbonding electrons. Reprinted with
permission from [24]. Copyright 2001 IOP Publishing Ltd.
29
lines for the spin-resolved energy levels, such as the 1s, 2p 1/2 , and 2p 3/2 of Cu.
Electronic occupation of the core bands often approximates the Gaussian or the
Lorentz type functions in decomposing the spectral peaks.
2.3 BOLS-NEP-LBA Notion
2.3.1 Local Hamiltonian Perturbation
Atomic CN is the primary variable that determines the CLS for undercoordinated
systems. Any change of the CN will relax the bond in length and energy accordingly,
which perturbs the V cryst (r). Possible factors of perturbation include:
(1) Undercoordination induced bond contraction, charge densification, localization,
entrapment, and polarization.
(2) Hetero-coordination induced bond nature alteration, bond relaxation, entrapment, or polarization.
(3) Radiation induced ionization associated with the “initial-final states” relaxation
during experiment.
(4) External bias caused charge accumulation of the tested specimen.
(5) Mechanical or thermal field induced bond relaxation in length and energy.
The zeroth approximation of the interatomic potential dictates the CLS.
Figure 2.2a illustrates bond length and energy (d, E) relaxation along the modulation function f (x) under a certain stimulus x such as the atomic CN, mechanical,
0.6
0.8
1.0
1.2
-1.5
-1.0
-0.5
0.0
0.5
C
-m
i
(E
i
/E
b
)
f(x)
C i
(a)
(b)
Fig. 2.2 Potentials of a dimer bond relaxing under external stimulus x. a Valley of the pairing
potential u(r, E) corresponds to bond length and energy (d, E b ) that relax along the modulation
function f (x) under stimulus x (x can be pressure, temperature or coordination environment, etc.).
b Bond order loss shortens and strengthens bonds between undercoordinated atoms at the bonding
network terminals such as sites of defects and skins of nanocrystals, which cause local densification
and entrapment of the bonding electrons, and polarization of nonbonding electrons. Reprinted with
permission from [24]. Copyright 2001 IOP Publishing Ltd.