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Changqing Sun - One of the best experts on this subject based on the ideXlab platform.
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coordination resolved local bond relaxation Electron Binding Energy shift and debye temperature of ir solid skins
Applied Surface Science, 2014Co-Authors: Yan Wang, Yongli Huang, Xuexian Yang, Yezi Yang, Changqing SunAbstract:Abstract Numerical reproduction of the measured 4f7/2 Energy shift of Ir(1 0 0), (1 1 1), and (2 1 0) solid skins turns out the following: (i) the 4f7/2 level of an isolated Ir atom shifts from 56.367 eV to 60.332 eV by 3.965 eV upon bulk formation; (ii) the local Energy density increases by up to 130% and the atomic cohesive Energy decreases by 70% in the skin region compared with the bulk values. Numerical match to observation of the temperature dependent Energy shift derives the Debye temperature that varies from 285.2 K (Surface) to 315.2 K (Bulk). We clarified that the shorter and stronger bonds between under-coordinated atoms cause local densification and quantum entrapment of Electron Binding Energy, which perturbs the Hamiltonian and the core shifts in the skin region.
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coordination resolved local bond contraction and Electron Binding Energy entrapment of si atomic clusters and solid skins
Journal of Applied Physics, 2014Co-Authors: Yan Wang, Yongli Huang, Xi Zhang, Ting Zhang, Changqing SunAbstract:Consistency between x-ray photoElectron spectroscopy measurements and density-function theory calculations confirms our bond order-length-strength notation-incorporated tight-Binding theory predictions on the quantum entrapment of Si solid skin and atomic clusters. It has been revealed that bond-order deficiency shortens and strengthens the Si-Si bond, which results in the local densification and quantum entrapment of the core and valence Electrons. Unifying Si clusters and Si(001) and (111) skins, this mechanism has led to quantification of the 2p Binding Energy of 96.089 eV for an isolated Si atom, and their bulk shifts of 2.461 eV. Findings evidence the significance of atomic undercoordination that is of great importance to device performance.
Yan Wang - One of the best experts on this subject based on the ideXlab platform.
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coordination resolved local bond relaxation Electron Binding Energy shift and debye temperature of ir solid skins
Applied Surface Science, 2014Co-Authors: Yan Wang, Yongli Huang, Xuexian Yang, Yezi Yang, Changqing SunAbstract:Abstract Numerical reproduction of the measured 4f7/2 Energy shift of Ir(1 0 0), (1 1 1), and (2 1 0) solid skins turns out the following: (i) the 4f7/2 level of an isolated Ir atom shifts from 56.367 eV to 60.332 eV by 3.965 eV upon bulk formation; (ii) the local Energy density increases by up to 130% and the atomic cohesive Energy decreases by 70% in the skin region compared with the bulk values. Numerical match to observation of the temperature dependent Energy shift derives the Debye temperature that varies from 285.2 K (Surface) to 315.2 K (Bulk). We clarified that the shorter and stronger bonds between under-coordinated atoms cause local densification and quantum entrapment of Electron Binding Energy, which perturbs the Hamiltonian and the core shifts in the skin region.
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coordination resolved local bond relaxation and Electron Binding Energy shift of pb solid skins and atomic clusters
Journal of Materials Chemistry C, 2014Co-Authors: Yan Wang, Yongli Huang, Wei Zhou, Chang Q SunAbstract:Lead (Pb) demonstrates pronounced Energy states pertaining to undercoordinated skin and edge atoms. The physical origin of these excessive states still remains unclear. Here, we show that the consistency between the density functional theory calculations and photoElectron spectroscopy measurements confirmed our theoretical predictions on the 5d core-level shift of Pb skins and clusters. It is clarified that shorter and stronger bonds between the undercoordinated atoms cause the local densification and entrapment of core Electrons, which, in turn, polarize the otherwise conducting Electrons in the skins and edges, resulting in the respective Electron Binding-Energy shift. Numerical analysis has revealed that 5d5/2 level shifts from 18.283 eV for an isolated Pb atom to 3.478 eV upon bulk formation. Meanwhile, this strategy has enabled the determination of local bond length, bond Energy, Binding Energy density, and atomic cohesive Energy at the undercoordinated atomic sites.
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coordination resolved local bond contraction and Electron Binding Energy entrapment of si atomic clusters and solid skins
Journal of Applied Physics, 2014Co-Authors: Yan Wang, Yongli Huang, Xi Zhang, Ting Zhang, Changqing SunAbstract:Consistency between x-ray photoElectron spectroscopy measurements and density-function theory calculations confirms our bond order-length-strength notation-incorporated tight-Binding theory predictions on the quantum entrapment of Si solid skin and atomic clusters. It has been revealed that bond-order deficiency shortens and strengthens the Si-Si bond, which results in the local densification and quantum entrapment of the core and valence Electrons. Unifying Si clusters and Si(001) and (111) skins, this mechanism has led to quantification of the 2p Binding Energy of 96.089 eV for an isolated Si atom, and their bulk shifts of 2.461 eV. Findings evidence the significance of atomic undercoordination that is of great importance to device performance.
Kit H. Bowen - One of the best experts on this subject based on the ideXlab platform.
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photoElectron spectroscopic study of dipole bound and valence bound nitromethane anions formed by rydberg Electron transfer
Journal of Chemical Physics, 2020Co-Authors: Gaoxiang Liu, Sandra M Ciborowski, Jacob D Graham, Allyson M Buytendyk, Kit H. BowenAbstract:Close-lying dipole-bound and valence-bound states in the nitromethane anion make this molecule an ideal system for studying the coupling between these two Electronically different states. In this work, dipole-bound and valence-bound nitromethane anions were generated by Rydberg Electron transfer and characterized by anion photoElectron spectroscopy. The presence of the dipole-bound state was demonstrated through its photoElectron spectral signature, i.e., a single narrow peak at very low Electron Binding Energy, its strong Rydberg quantum number, n*, dependence, and its relatively large anisotropy parameter, β. This work goes the furthest yet in supporting the doorway model of Electron attachment to polar molecules.
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Electron Binding Energy Spectra of AlnMo- Clusters: Measurements, Calculations and Theoretical Analysis
The Journal of Physical Chemistry C, 2018Co-Authors: Paulo H. Acioli, Xinxing Zhang, Kit H. Bowen, Julius JellinekAbstract:Results of photoElectron spectroscopy measurements and density functional theory complemented with correction scheme calculations on Electron Binding Energy (EBE) spectra of anionic AlnMo, n = 3–5 and 7, clusters are presented and analyzed. The analysis points to the important role of dynamical fluxionality and multiplicity of structural forms as contributing factors in the measured spectra. Using the example of Al4Mo– as a paradigmatic case, the separate roles of size, structure/symmetry, and composition in evolving the EBE spectra of precursor pure clusters (in this case, Al4– and Al5–) into those of bimetallic clusters are demonstrated utilizing a new methodology we developed recently (J. Phys. Chem. C 2017, 121, 16665).
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excess Electron attachment to the nucleoside pair 2 deoxyadenosine da 2 deoxythymidine dt
Journal of Physical Chemistry B, 2016Co-Authors: Piotr Storoniak, Yeon Jae Ko, Haopeng Wang, Kit H. BowenAbstract:The 2′-deoxyadenosine···2′-deoxythymidine (dAdT•–) radical anion nucleoside pair has been investigated both experimentally and theoretically in the gas phase. The vertical detachment Energy (VDE) and adiabatic Electron affinity (AEA) were determined by anion photoElectron spectroscopy (PES). The measured photoElectron spectrum features a broad band having an onset at ∼1.1 eV and a maximum at the Electron Binding Energy (EBE) ranging from 1.7 to 1.9 eV. Calculations performed at the M06-2X/6-31++G** level reveal that the observed PES signal is probably due to a dAdT•– complex in which the thymine of the dT nucleoside forms hydrogen bonds that engage its O7 and O8 atoms as well as the 3′- and 5′-hydroxyl groups of 2′-deoxyadenosine (dA), while dT’s 3′-hydroxyl group interacts with the N1 of dA. In this heterodimer, the excess Electron is entirely located on thymine. The biologically relevant Watson–Crick arrangement of the dAdT•– dimer was found to be substantially less stable (by ∼19 kcal mol–1 in Gibbs fr...
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PhotoElectron spectroscopy and computational modeling of thymidine homodimer anions.
Journal of Physical Chemistry B, 2012Co-Authors: Piotr Storoniak, Yeon Jae Ko, Haopeng Wang, Kit H. BowenAbstract:The intact thymidine homodimer anion (dT2–) was generated in the gas phase using an infrared desorption/photoemission source and recorded by a pulsed photoElectron spectrometer. The photoElectron spectrum (PES) revealed a broad signal with the maximum at Electron Binding Energy ∼2.0 eV and the threshold value at 1.1 eV. The relative energies and vertical detachment energies of the possible anion structures were calculated at the B3LYP/6-31++G(d,p) level. Here we report that the most stable anion radical homodimer geometries observed in the PES are the anionic nucleoside coordinated by the O8 atom of thymine to the deoxyribose of the second neutral nucleoside. Unlike previous experimental–computational studies on anionic complexes involving nucleobases with proton donors, the Electron-induced proton-transferred structures are not responsible for the shape of the PES of dT2–.
Kenneth D Jordan - One of the best experts on this subject based on the ideXlab platform.
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exploring the correlation between network structure and Electron Binding Energy in the h2o 7 cluster through isomer photoselected vibrational predissociation spectroscopy and ab initio calculations addressing complexity beyond types i iii
Journal of Chemical Physics, 2008Co-Authors: Joseph R Roscioli, Nathan I Hammer, Mark A Johnson, Kadir Diri, Kenneth D JordanAbstract:We report a combined photoElectron and vibrational spectroscopy study of the (H(2)O)(7)(-) cluster anions in order to correlate structural changes with the observed differences in Electron Binding energies of the various isomers. PhotoElectron spectra of the (H(2)O)(7)(-) . Ar(m) clusters are obtained over the range of m=0-10. These spectra reveal the formation of a new isomer (I') for m>5, the Electron Binding Energy of which is about 0.15 eV higher than that of the type I form previously reported to be the highest Binding Energy species [Coe et al., J. Chem. Phys. 92, 3980 (1990)]. Isomer-selective vibrational predissociation spectra are obtained using both the Ar dependence of the isomer distribution and photochemical depopulation of the more weakly (Electron) Binding isomers. The likely structures of the isomers at play are identified with the aid of Electronic structure calculations, and the Electron Binding energies, as well as harmonic vibrational spectra, are calculated for 28 low-lying forms for comparison with the experimental results. The HOH bending spectrum of the low Binding type II form is dominated by a band that is moderately redshifted relative to the bending origin of the bare water molecule. Calculations trace this feature primarily to the bending vibration localized on a water molecule in which a dangling H atom points toward the Electron cloud. Both higher Binding forms (I and I') display the characteristic patterns in the bending and OH stretching regions signaling Electron attachment primarily to a water molecule in an AA Binding site, a persistent motif found in non-isomer-selective spectra of the clusters up to (H(2)O)(50)(-).
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exploring the correlation between network structure and Electron Binding Energy in the h2o 7 cluster through isomer photoselected vibrational predissociation spectroscopy and ab initio calculations addressing complexity beyond types i iii
Journal of Chemical Physics, 2008Co-Authors: Joseph R Roscioli, Nathan I Hammer, Mark A Johnson, Kadir Diri, Kenneth D JordanAbstract:We report a combined photoElectron and vibrational spectroscopy study of the (H2O)7− cluster anions in order to correlate structural changes with the observed differences in Electron Binding energies of the various isomers. PhotoElectron spectra of the (H2O)7−⋅Arm clusters are obtained over the range of m=0–10. These spectra reveal the formation of a new isomer (I′) for m>5, the Electron Binding Energy of which is about 0.15eV higher than that of the type I form previously reported to be the highest Binding Energy species [Coe et al., J. Chem. Phys. 92, 3980 (1990)]. Isomer-selective vibrational predissociation spectra are obtained using both the Ar dependence of the isomer distribution and photochemical depopulation of the more weakly (Electron) Binding isomers. The likely structures of the isomers at play are identified with the aid of Electronic structure calculations, and the Electron Binding energies, as well as harmonic vibrational spectra, are calculated for 28 low-lying forms for comparison with t...
Yongli Huang - One of the best experts on this subject based on the ideXlab platform.
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coordination resolved local bond relaxation Electron Binding Energy shift and debye temperature of ir solid skins
Applied Surface Science, 2014Co-Authors: Yan Wang, Yongli Huang, Xuexian Yang, Yezi Yang, Changqing SunAbstract:Abstract Numerical reproduction of the measured 4f7/2 Energy shift of Ir(1 0 0), (1 1 1), and (2 1 0) solid skins turns out the following: (i) the 4f7/2 level of an isolated Ir atom shifts from 56.367 eV to 60.332 eV by 3.965 eV upon bulk formation; (ii) the local Energy density increases by up to 130% and the atomic cohesive Energy decreases by 70% in the skin region compared with the bulk values. Numerical match to observation of the temperature dependent Energy shift derives the Debye temperature that varies from 285.2 K (Surface) to 315.2 K (Bulk). We clarified that the shorter and stronger bonds between under-coordinated atoms cause local densification and quantum entrapment of Electron Binding Energy, which perturbs the Hamiltonian and the core shifts in the skin region.
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coordination resolved local bond relaxation and Electron Binding Energy shift of pb solid skins and atomic clusters
Journal of Materials Chemistry C, 2014Co-Authors: Yan Wang, Yongli Huang, Wei Zhou, Chang Q SunAbstract:Lead (Pb) demonstrates pronounced Energy states pertaining to undercoordinated skin and edge atoms. The physical origin of these excessive states still remains unclear. Here, we show that the consistency between the density functional theory calculations and photoElectron spectroscopy measurements confirmed our theoretical predictions on the 5d core-level shift of Pb skins and clusters. It is clarified that shorter and stronger bonds between the undercoordinated atoms cause the local densification and entrapment of core Electrons, which, in turn, polarize the otherwise conducting Electrons in the skins and edges, resulting in the respective Electron Binding-Energy shift. Numerical analysis has revealed that 5d5/2 level shifts from 18.283 eV for an isolated Pb atom to 3.478 eV upon bulk formation. Meanwhile, this strategy has enabled the determination of local bond length, bond Energy, Binding Energy density, and atomic cohesive Energy at the undercoordinated atomic sites.
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coordination resolved local bond contraction and Electron Binding Energy entrapment of si atomic clusters and solid skins
Journal of Applied Physics, 2014Co-Authors: Yan Wang, Yongli Huang, Xi Zhang, Ting Zhang, Changqing SunAbstract:Consistency between x-ray photoElectron spectroscopy measurements and density-function theory calculations confirms our bond order-length-strength notation-incorporated tight-Binding theory predictions on the quantum entrapment of Si solid skin and atomic clusters. It has been revealed that bond-order deficiency shortens and strengthens the Si-Si bond, which results in the local densification and quantum entrapment of the core and valence Electrons. Unifying Si clusters and Si(001) and (111) skins, this mechanism has led to quantification of the 2p Binding Energy of 96.089 eV for an isolated Si atom, and their bulk shifts of 2.461 eV. Findings evidence the significance of atomic undercoordination that is of great importance to device performance.