Influence of water on the properties of an Au/Mpy/Pd metal/molecule/metal junction

The geometric and electronic structure of the metal–molecule interface in metal/molecule/metal junctions is of great interest since it affects the functionality of such units in possible nanoelectronic devices. We have investigated the interaction between water and a palladium monolayer of a Au(111)/4-mercaptopyridine/Pd junction by means of DFT calculations. A relatively strong bond between water and the palladium monolayer of the Au/Mpy/Pd complex is observed via a one-fold bond between the oxygen atom of the water molecule and a Pd atom. An isolated H2O molecule adsorbs preferentially in a flat-lying geometry on top of a palladium atom that is at the same time also bound to the nitrogen atom of a Mpy molecule of the underlying self-assembled monolayer. The electronic structure of these Pd atoms is considerably modified which is reflected in a reduced local density of states at the Fermi energy. At higher coverages, water can be arranged in a hexagonal ice-like bilayer structure in analogy to water on bulk metal surfaces, but with a much stronger binding which is dominated by O–Pd bonds.

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ELECTRONIC STRUCTURE OF SHORT CARBON NANOBELLS

Modern Physics Letters B ◽

10.1142/s0217984903005275 ◽

2003 ◽

Vol 17 (09) ◽

pp. 375-382 ◽

Cited By ~ 12

Author(s):

G. L. ZHAO ◽

D. BAGAYOKO ◽

E. G. WANG

Keyword(s):

Electronic Structure ◽

Density Functional ◽

Local Density ◽

Emission Characteristics ◽

Local Density Of States ◽

Nitrogen Doped ◽

Local Density Functional ◽

Nitrogen Doped Carbon ◽

Short Carbon ◽

Open Edge

We performed local density functional calculations for the electronic structure of short carbon nanobells. The calculated local density of states of the nanobells revealed field emission characteristics that agree with experimental observations. We also performed total energy calculations to study the structural stability and a related possible growth mechanism of the nanobells. In the nitrogen-doped carbon nanobells, nitrogen atoms that are attracted to the open-edge sites of the carbon nanobells appear to stop the growth of the nanostructures.

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Ab-Initio Molecular Dynamics Approach to the Study of Grain Boundaries in Semiconductors

MRS Proceedings ◽

10.1557/proc-141-333 ◽

1988 ◽

Vol 141 ◽

Author(s):

E. Tarnow ◽

P. D. Bristowe ◽

J. D. Joannopoulos ◽

M. C. Payne

Keyword(s):

Molecular Dynamics ◽

Electronic Structure ◽

Ab Initio ◽

Local Density ◽

Ab Initio Molecular Dynamics ◽

Local Density Of States ◽

High Angle ◽

Surface Information ◽

Atomic And Electronic Structure ◽

Translation State

AbstractUsing an ab-initio molecular dynamics approach based on the Car-Parrinello method, the detailed atomic and electronic structure of a high-angle grain boundary in germanium is determined by investigating its energy-translation surface. Information concerning the coordination of the lowest energy configuration, its translation state, volume change, structure factor and local density of states is obtained.

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Electronic Structure of Substitutionally Disordered Alloys: Direct Configurational Averaging

MRS Proceedings ◽

10.1557/proc-278-307 ◽

1992 ◽

Vol 278 ◽

Author(s):

C. Wolverton ◽

D. De Fontaine ◽

H. Dreysse ◽

G. Ceder

Keyword(s):

Electronic Structure ◽

Band Structure ◽

Local Density ◽

Tight Binding ◽

Ternary Alloys ◽

Orbital Method ◽

Thermodynamic Quantities ◽

Local Density Of States ◽

Disordered Alloys ◽

Effective Cluster

AbstractThe method of direct configurational averaging (DCA) has been proposed to study the electronic structure of disordered alloys. Local density of states and band structure energies are obtained by averaging over a small number of configrations within a tight-binding Hamiltonian. Effective cluster interactions, the driving quantities for ordering in solids, are computed for various alloys using a tight-binding form of the linearized muffin-tin orbital method (TB-LMTO). The DCA calculations are used to determine various energetic and thermodynamic quantities for binary and ternary alloys.

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Calculations of the Electronic Structure of Vacancies in a-Si:H

MRS Proceedings ◽

10.1557/proc-291-349 ◽

1992 ◽

Vol 291 ◽

Author(s):

Ariel A. Valladares ◽

L. Enrique Sansores

Keyword(s):

Electronic Structure ◽

Charge Density ◽

Density Of States ◽

Energy Gap ◽

Local Density ◽

Amorphous Solids ◽

Local Density Of States ◽

Hydrogen Atoms ◽

Hartree Fock ◽

Cluster Calculations

ABSTRACTThe electronic structure of random clusters has been used in the literature as representative of the electronic structure of random solids. In this work a calculation of the local density of states (LDOS) and charge density contours for clusters of the type XSi20H28 with X an Si atom, a vacancy or 4 hydrogen atoms, has been carried out. The method used was a pseudopotential SCF Hartree-Fock and the HONDO program. It is found that the generation of a vacancy in the center of the cluster (removal of the central Si atom), introduces p-like states in the energy gap of the LDOS for the region near the center of the cluster. The saturation of the dangling bonds of the vacancy with 4 hydrogen atoms removes the states within the gap. These results are also borne out by the charge density contours, thereby reinforcing the importance of amorphous cluster calculations in the understanding of the electronic structure of amorphous solids.

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INFLUENCE OF A TIP/SAMPLE INTERACTION ON SCANNING TUNNELING SPECTROSCOPY DATA

Surface Review and Letters ◽

10.1142/s0218625x95000248 ◽

1995 ◽

Vol 02 (02) ◽

pp. 219-223 ◽

Cited By ~ 2

Author(s):

V.G. ZAVODINSKY ◽

I.A. KUYANOV

Keyword(s):

Electronic Structure ◽

Local Density ◽

Scanning Tunneling Spectroscopy ◽

Scanning Tunneling ◽

Local Density Of States ◽

Tunnel Current ◽

Free Sample ◽

Discrete Variational Method ◽

Local Electronic Structure ◽

Sample Distance

The electronic states and the tunnel current for the W/Si and W/Al tip/sample systems were calculated by the first-principles discrete-variational method of the local-density approximation. It was found that the local-electronic structure of the Si surface resembles that of a free sample even for the tip/sample distances of 2–3 Å. The electronic structure of the Al surface is more sensitive to the tip/sample interaction and approaches the free surface form when the tip/sample distance is larger than 4 Å. The local density of states of the W tip also depends on the tip/sample distance and must be taken into account in the tunnel-current calculations and in the interpretations of the STS data.

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EELS as a Probe of Local Electronic Structure and Cohesion

Microscopy and Microanalysis ◽

10.1017/s1431927600027045 ◽

2001 ◽

Vol 7 (S2) ◽

pp. 194-195

Author(s):

David A. Muller

Keyword(s):

Mechanical Properties ◽

Electronic Structure ◽

Fine Structure ◽

Grain Boundary ◽

Grain Boundaries ◽

Local Density ◽

The Other ◽

Local Density Of States ◽

Materials Properties ◽

Local Electronic Structure

There is an intimate connection between the electronic structure of a material and its physical properties. to change one, is to change the other. Some of the most striking illustrations of this relationship can be found at grain boundaries in metals and their alloys. Here, the most important changes in cohesion can be described by changes in the local density of states (LDOS), which in turn can be measured using EELS [1]. The first demonstration that EELS could be used to connect the electronic and mechanical properties of a material was in revealing the role that boron has in restoring a bulk-like bonding to grain boundaries in Ni3Al [2,3]. Boron was known to change the fracture mode in Ni3Al from intergranular to transgranular, possibly by enhancing grain boundary cohesion.What interested me in this project, when John Silcox first suggested it as a thesis topic, was the potential of using the EELS fine structure to measure materials properties directly.

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Estados de superficie y estados resonantes del Pd (111)

Respuestas ◽

10.22463/0122820x.1324 ◽

2018 ◽

Vol 23 (1) ◽

pp. 13

Author(s):

Hernan Javier Herrera ◽

A. Rubio Ponce ◽

D. Olguín

Keyword(s):

Electronic Structure ◽

Density Of States ◽

Electronic Band Structure ◽

Local Density ◽

Surface States ◽

Infinite Medium ◽

Crystallographic Direction ◽

Local Density Of States ◽

Electronic Band ◽

Resonant States

La motivación del presente trabajo se fundamenta en la importancia del Paladio en procesos de catálisis y sus propiedades electrónicas. En tal sentido, se presenta un estudio detallado de la estructura electrónica de bandas del Paladio en la dirección cristalográfica (111). De tal manera, se verificó que la densidad local de estados proyectada en el volumen, concordara con los resultados obtenidos para el caso del medio infinito previamente reportados, para ello, se realizó un estudio detallado de diferentes estados de superficie y estados resonantes característicos del Paladio en la dirección cristalográfica (111). Se halló que los resultados obtenidos se comparan con los valores publicados en la literatura, y se hizo la predicción de diferentes estados no reportados aún.Palabras clave: Estados de superficie, estados resonantes, estructura electrónica de bandas. AbstractThe motivation of this work is based on the importance of Palladium in processes such as catalysis and hence the need to know its electronic properties. We present a detailed study of the electronic structure of Palladium bands in the crystallographic direction (111). First we verify that the local density of states, projected in the volume, agrees with the results obtained for the case of the infinite medium previously reported. Next, a detailed study is made of different surface states and characteristic resonant states of the Palladium in the crystallographic direction (111). It was found that the results obtained are compared with the values published in the literature, and the prediction of different states not yet reported is made.Keywords: Surface states, resonant states, local density of states, bulk projected electronic band structure. ResumoA motivação do presente trabalho baseia-se na importância do paládio nos processos de catálise e suas propriedades eletrônicas. A este respeito, um estudo detalhado da estrutura eletrônica das bandas de paládio na direção cristalográfica (111) é apresentado. Desta forma, verificou-se que a densidade local de estados projetados no volume, vai concordar com os resultados obtidos para o caso do meio infinito relatado anteriormente, para isso, foi feito um estudo detalhado dos diferentes estados de superfície e estados ressonantes característicos do paládio. na direção cristalográfica (111). Verificou-se que os resultados obtidos são comparados com os valores publicados na literatura, e a predição dos diferentes estados ainda não relatados foi feita.Palavras-chave: Estados de superfície, estados ressonantes, estrutura de banda eletrônica.

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Electronic Structures at Metal/Alumina Interfaces

MRS Proceedings ◽

10.1557/proc-193-155 ◽

1990 ◽

Vol 193 ◽

Author(s):

M. Kohyama ◽

S. Kose ◽

M. Kinoshita ◽

R. Yamamoto

Keyword(s):

Electronic Structure ◽

Chemical Bond ◽

Photoelectron Spectroscopy ◽

Electronic Structures ◽

Local Density ◽

Tight Binding ◽

Theoretical Method ◽

Local Density Of States ◽

Spectroscopy Study ◽

Metal Atoms

ABSTRACTThe electronic structure of the interface between α-Al2O3(0001) and Nb layers has been calculated using the empirical tight-binding method and the slab model. It has been shown that a direct chemical bond of both covalent and ionic characters can be established at the interface between the surface O atoms of α-Al2O3 and the Nb atoms, which is consistent with the recent photoelectron spectroscopy study. General trends of the electronic structure and chemical bond at the interfaces between α-Al2O3.(0001) and a series of 4d transition metals have been examined using the same theoretical method. In all cases, there exist similar interactions between the surface O atoms and the metal atoms, and it has been observed that the occupancy in the portion of the antibonding peaks of the local density of states at the interface increases as the atomic number of the transition metal increases.

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ELECTRONIC STRUCTURE OF STRAINED VANADIUM OVERLAYERS ON W(100) AND Ta(100)

Surface Review and Letters ◽

10.1142/s0218625x96002503 ◽

1996 ◽

Vol 03 (04) ◽

pp. 1505-1509 ◽

Cited By ~ 6

Author(s):

R. DE COSS

Keyword(s):

Electronic Structure ◽

Density Of States ◽

Lattice Mismatch ◽

Local Density ◽

Tight Binding ◽

Local Density Of States ◽

Tight Binding Approximation ◽

Surface Electronic Structure ◽

Topmost Layer ◽

Surface Green Function

We study the role of hybridization and overlayer–substrate lattice mismatch in determining the surface electronic structure of strained V monolayers and bilayers on W(100) and Ta(100). The local density of states is calculated in the tight-binding approximation within the surface-Green-function-matching formalism. For one monolayer of V on W(100) and Ta(100), the strong monolayer–substrate 3d–5d hybridization determines the features of the surface local density of states, with essentially no differences between 1V/W(100) and 1V/Ta(100). For the bilayer we find that the electronic structure of the topmost layer depends strongly on the lattice mismatch between overlayer and substrate. In particular, we find that the surface local density of states at the Fermi level in 2V/Ta(100) is 69% higher than in 1V/Ta(100); the lattice mismatch between bulk constants of V and Ta is 9.0%. These results indicate that strain induces strong band narrowing in vanadium overlayers on transition metals, despite the large overlayer–substrate hybridization, but depends critically on the film thickness.

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Supersymmetric Cluster Expansions and Applications to Random Schrödinger Operators

Mathematical Physics Analysis and Geometry ◽

10.1007/s11040-021-09375-5 ◽

2021 ◽

Vol 24 (1) ◽

Author(s):

Luca Fresta

Keyword(s):

Density Of States ◽

Local Density ◽

Schrödinger Operators ◽

Random Schrödinger Operators ◽

Schrodinger Operators ◽

Local Density Of States ◽

Weak Disorder ◽

Cluster Expansions ◽

Strong Disorder ◽

Lifshitz Tail

AbstractWe study discrete random Schrödinger operators via the supersymmetric formalism. We develop a cluster expansion that converges at both strong and weak disorder. We prove the exponential decay of the disorder-averaged Green’s function and the smoothness of the local density of states either at weak disorder and at energies in proximity of the unperturbed spectrum or at strong disorder and at any energy. As an application, we establish Lifshitz-tail-type estimates for the local density of states and thus localization at weak disorder.

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