Tight-binding analysis of the electronic states in AlAs with N isoelectronic impurities

2014 ◽  
Vol 115 (12) ◽  
pp. 123501 ◽  
Author(s):  
M. Jo ◽  
T. Mano ◽  
Y. Sakuma ◽  
K. Sakoda
Keyword(s):  
Tight Binding ◽  
Electronic States ◽  
Binding Analysis ◽  
Isoelectronic Impurities

The electronic properties of (methylxguanidinium)[Ni(dmit)2]2. A two-orbital tight-binding analysis

1996 ◽  
Vol 97 (9) ◽  
pp. 737-740 ◽  
Author(s):  
P.M. Paulus ◽  
H.B. Brom ◽  
Y.S.J. Veldhuizen ◽  
W.J.A. Maaskant
Keyword(s):  
Electronic Properties ◽  
Tight Binding ◽  
Binding Analysis

Chemisorption of Ordered Overlayer on a Tight-Binding Metal Surface Two-Level Adsorbate

1982 ◽  
Vol 37 (10) ◽  
pp. 1147-1164
Author(s):  
K. Masuda
Keyword(s):  
Phase Shift ◽  
Transition Metal ◽  
Density Of States ◽  
Tight Binding ◽  
Electronic States ◽  
Bridge Site ◽  
Bonding Interaction ◽  
Model Transition ◽  
Adsorbate Structure ◽  
Shift Technique

The chemisorption of a two-level (at E1 and E2) adsorbate on the (001) surface of a tightbinding metal is investigated using the Green's function formalism and the phase shift technique. The adorbital density of states (DOS)ϱa(E) as well as the change in the electronic DOS Δϱ(E; E1, E2) due to chemisorption are calculated for the ordered overlayers with c(2 x 2), p(2 x 1), p(2 X 2), p(4 X 1) and c(4 X 2) structures. It is assumed that the chemisorbed species sit over the twofold bridge site of the (001) surface of the model transition metal and have a π-bonding interaction with the two substrate atoms. It is shown that the electronic states of the overlayers are very sensitive to the adsorbate coverage (0), adsorbate structure and adsorbate species (one level or two level adsorbates). Furthermore, it is shown that there are marked differences in the Δϱ(E) curves between the chemisorption of two level adsorbates Δϱ(E; E1, E2) and that of single level adsorbates Δϱ(E; E1) + Δϱ(E; E2) (simulating the changes in the electronic DOS during the dissociation of diatomic molecules).

scholarly journals Geometries and Electronic States of Divacancy Defect in Finite-Size Hexagonal Graphene Flakes

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Lili Liu ◽  
Shimou Chen
Keyword(s):  
Ground State ◽  
First Principles ◽  
Density Functional ◽  
Singlet State ◽  
Tight Binding ◽  
Finite Size ◽  
Electronic States ◽  
Closed Shell ◽  
Graphene Flakes ◽  
Self Consistent

The geometries and electronic properties of divacancies with two kinds of structures were investigated by the first-principles (U) B3LYP/STO-3G and self-consistent-charge density-functional tight-binding (SCC-DFTB) method. Different from the reported understanding of these properties of divacancy in graphene and carbon nanotubes, it was found that the ground state of the divacancy with 585 configurations is closed shell singlet state and much more stable than the 555777 configurations in the smaller graphene flakes, which is preferred to triplet state. But when the sizes of the graphene become larger, the 555777 defects will be more stable. In addition, the spin density properties of the both configurations are studied in this paper.

Hybridization in Electronic States and Optical Properties of Covalent Amorphous Semiconductors

1999 ◽  
Vol 588 ◽  
Author(s):  
Yuzo Shinozuka
Keyword(s):  
Optical Properties ◽  
Spatial Correlation ◽  
Nearest Neighbor ◽  
Tight Binding ◽  
Electronic States ◽  
Amorphous Semiconductors ◽  
Transfer Energy ◽  
Binding Model ◽  
Covalent Bonds ◽  
Conduction Bands

AbstractThe electronic structure and optical properties of covalent amorphous semiconductors are theoretically studied with special attention to the s-p hybridization in electronic states and the spatial correlation in their mixing. One-dimensional tight binding model is used in which the interatomic transfer energy of an electron between nearest neighbor atoms depends linearly on their interatomic distance. All the electronic states are numerically calculated for a 150-atom system and the ensemble average is taken over 10 samples. Following results have been obtained. As the degree of randomness increases, the degree of hybridization decreases and rearrangements in the covalent bonds take place. The width of the band gap decreases but the gap remains rather long compared to a case where the spatial correlation is neglected. There appears a characteristic peak in the optical absorption spectrum, which reflects central peaks in the partial (s- or p-) density of states in the valence and conduction bands and is related to an electron localization caused by the spatial correlation.

A tight-binding analysis of cohesive properties in the Ni-Al system

1989 ◽  
Vol 1 (34) ◽  
pp. 5837-5845 ◽  
Author(s):  
C Colinet ◽  
A Bessoud ◽  
A Pasturel
Keyword(s):  
Tight Binding ◽  
Cohesive Properties ◽  
Binding Analysis
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