Chapter 2
Theory: Bond-Electron-Energy
Correlation
Abstract Electron binding energy shift directly features the change of bond energy
with coordination environments and chemical conditions, from which one can evaluate the local and quantitative information on the local bond length, bond energy,
core charge entrapment and valence electron polarization. Bonds and electrons associated with undercoordinated adams, point defects, skins, and nanostructures follows the BOLS-NEP notion but bonds associated with the hetero-coordinated and
the tetrahedrally-coordinated impurities and interfaces may subject to bond nature
alteration and the local electrons may subject to entrapment or polarization.
Highlights
• One can shift elelctron binding energy from that of an isolated atom by perturbing
Hamiltonian.
• The core-level shifts (CLS) with the bond energy transiting from one equilibrium
to the other.
• Atomic irregular-CN shifts the CLS positively by bond contraction, core electron entrapment.
• Nonbonding electron polarization screens the local potential and offsets the CLS
contrastingly.
2.1 Atomic Coordination Classification
Table 2.1 classifies substances according to their atomic coordination environments.
Atomic undercoordination means an atom with fewer neighbors than it is in the bulk
fcc structural standard of z b = 12. For an isolated atom, z = 0, which happens only at
0 K ideally [1] or in the gaseous phase. Undercoordination (0 < z < 12) is ubiquitous
to adatoms, defects, terrace edges, grain boundaries, skins, of solid species and
nanostructures of various shapes and sizes. Monatomic chains and monolayer atomic
sheets are ideal cases of one- and two-dimensional undercoordination systems, which
possess tremendously revolutionary properties [2].
© The Editor(s) (if applicable) and The Author(s), under exclusive license
to Springer Nature Singapore Pte Ltd. 2020
C. Q. Sun, Electron and Phonon Spectrometrics,
https://doi.org/10.1007/978-981-15-3176-7_2
25
Theory: Bond-Electron-Energy
Correlation
Abstract Electron binding energy shift directly features the change of bond energy
with coordination environments and chemical conditions, from which one can evaluate the local and quantitative information on the local bond length, bond energy,
core charge entrapment and valence electron polarization. Bonds and electrons associated with undercoordinated adams, point defects, skins, and nanostructures follows the BOLS-NEP notion but bonds associated with the hetero-coordinated and
the tetrahedrally-coordinated impurities and interfaces may subject to bond nature
alteration and the local electrons may subject to entrapment or polarization.
Highlights
• One can shift elelctron binding energy from that of an isolated atom by perturbing
Hamiltonian.
• The core-level shifts (CLS) with the bond energy transiting from one equilibrium
to the other.
• Atomic irregular-CN shifts the CLS positively by bond contraction, core electron entrapment.
• Nonbonding electron polarization screens the local potential and offsets the CLS
contrastingly.
2.1 Atomic Coordination Classification
Table 2.1 classifies substances according to their atomic coordination environments.
Atomic undercoordination means an atom with fewer neighbors than it is in the bulk
fcc structural standard of z b = 12. For an isolated atom, z = 0, which happens only at
0 K ideally [1] or in the gaseous phase. Undercoordination (0 < z < 12) is ubiquitous
to adatoms, defects, terrace edges, grain boundaries, skins, of solid species and
nanostructures of various shapes and sizes. Monatomic chains and monolayer atomic
sheets are ideal cases of one- and two-dimensional undercoordination systems, which
possess tremendously revolutionary properties [2].
© The Editor(s) (if applicable) and The Author(s), under exclusive license
to Springer Nature Singapore Pte Ltd. 2020
C. Q. Sun, Electron and Phonon Spectrometrics,
https://doi.org/10.1007/978-981-15-3176-7_2
25