New Surface Atomic Structures for III-V(110)-p(1x1)-Sb(1ML):Chemical Bonding and Electronic Structure

1990 ◽  
Vol 193 ◽  
Author(s):  
John P. LaFemina ◽  
C. B. Duke ◽  
C. Maflhiot
Keyword(s):  
Electronic Structure ◽  
Coordination Chemistry ◽  
Total Energy ◽  
Small Molecule ◽  
Chemical Bonding ◽  
Energy Surface ◽  
Minimum Energy ◽  
Tight Binding ◽  
Atomic Structures

ABSTRACTTight-binding total energy computations are used to examine the chemical bonding and electronic structure for two new minimum-energy surface atomic structures for p(lxl) overlayers of Sb on III-V(110) surfaces. The bonding in each of these structures is unique, having no analog in either the bulk or small molecule coordination chemistry of these materials, and is a phenomenon uniquely associated with the constrained epitaxical growth of the Sb overlayer.

Simulation of Vacancy Pairs in GaN Using Tight-Binding Molecular Dynamics

1997 ◽  
Vol 482 ◽  
Author(s):  
Derrick E. Boucher ◽  
Zoltán A. Gál ◽  
Gary G. DeLeo ◽  
W. Beall Fowler
Keyword(s):  
Molecular Dynamics ◽  
Electronic Structure ◽  
Total Energy ◽  
Formation Energy ◽  
Tight Binding ◽  
Md Simulations ◽  
Shallow Donor ◽  
Shallow Acceptor ◽  
Structure Geometry ◽  
Donor Character

AbstractThe electronic structure, geometry and energetics of Ga vacancy pairs and N vacancy pairs in both wurtzite and zincblende GaN are investigated via molecular dynamics (MD) simulations using an empirical tight-binding (TB) model with total energy capabilities and supercells containing up to 216 atoms. Our calculations suggest that, by pairing, N vacancies, which in isolation act as shallow donors, can lower their collective formation energy by about 5 eV. In doing so, however, these N vacancies lose their shallow-donor character as the lattice relaxes in response to this aggregation. Contrasting with the N vacancies, the Ga vacancies are found to retain their isolated shallow acceptor behavior and do not gain significant energy upon aggregation. The possible implications for larger aggregate defects are discussed.

New Tight-Binding Pair Potentials for Mineral Oxides: Application to β-Cassiterite (110), β-Tridymite (10TO) and Cristobalite (110)

1992 ◽  
Vol 278 ◽  
Author(s):  
T. J. Godin ◽  
John P. Lafemina
Keyword(s):  
Total Energy ◽  
Nearest Neighbor ◽  
Tight Binding ◽  
Insulating Materials ◽  
Atomic Structures ◽  
Pair Potentials ◽  
Mineral Oxides ◽  
Distant Neighbor

AbstractTight-binding, total-energy (TBTE) methods have successfully predicted surface atomic geometries for a variety of semiconducting and insulating materials that are well described by a nearest-neighbor model of interatomic interactions. However, little work has been done on distant-neighbor models, which are required to study many important mineral oxides. In this paper we demonstrate one way in which the TBTE methodology can be extended to these materials. To illustrate this approach, we calculate surface atomic structures for cassiterite SnO2 (110), β-cristobalite SiO2 (110) and βtridymite SiO2 (10TO).

Electronic Structure and Energetics of LaNi5, α-La2Ni10H and β-La2Ni10H14

1998 ◽  
Vol 513 ◽  
Author(s):  
H. Nakamura ◽  
D. Nguyen-Manh ◽  
D. G. Pettifor
Keyword(s):  
Electronic Structure ◽  
Total Energy ◽  
Charge Density ◽  
Tight Binding ◽  
Site Occupancy ◽  
Heat Of Formation ◽  
Hydrogen Atoms ◽  
Atomic Sphere ◽  
Sphere Approximation ◽  
Atomic Sphere Approximation

ABSTRACTThe electronic structure and energetics of LaNi5, its hydrogen solution (α-La2Ni10H) and its hydride (β-La2Ni10H14) were investigated by means of the tight-binding linear muffin-tin orbitals method within the atomic sphere approximation (TB-LMTO-ASA). Preferred site occupancy by the absorbed hydrogen atoms was investigated in terms of the charge density of the interstitial sites and the total energy, both of which indicate that the 6m site in the P6/mmm symmetry is the most preferred. A negative heat of formation of La2Ni10H14 was obtained from the total energy calculations.

Tight-binding description of the electronic structure and total energy of tin

2002 ◽  
Vol 82 (1) ◽  
pp. 47-61 ◽  
Author(s):  
Brahim Akdim ◽  
D. A. Papaconstantopoulos ◽  
M. J. Mehl
Keyword(s):  
Electronic Structure ◽  
Total Energy ◽  
Tight Binding

Electronic Structure and Total-Energy of FeSi2 Pseudomorphic Phases

1993 ◽  
Vol 320 ◽  
Author(s):  
Leo Miglio ◽  
Giovanna Malegori
Keyword(s):  
Thin Films ◽  
Electronic Structure ◽  
Molecular Beam Epitaxy ◽  
Total Energy ◽  
Density Of States ◽  
Molecular Beam ◽  
Tight Binding ◽  
Binding Parameters ◽  
Annealing Temperatures ◽  
Β Phase

ABSTRACTBy fitting orthogonal tight binding parameters to the ab inlio bands of Calciumfluorite FeSi2 (γ-phase) and Cesiumcloride FeSi, we calculate the electronic structure (bands and density of states) and the total-energy of the semiconductive, orthorombic β-phase and the disordered, cubic one. The latter, the γ and the β nfigurations, have been recently observed at different annealing temperatures in thin films grown on Si (111) by Molecular Beam Epitaxy. The transferability of our method among different phases allows for a comparison of the cohesive energy curves which, in turn, supplies an interpretation of the relative stability and the growth kinetics.

Effect of Chromium and Vanadium on Nanolayered Ternary Carbides: AB Initio Study

2009 ◽  
Vol 609 ◽  
pp. 239-242
Author(s):  
A.E. Merad ◽  
M.B. Kanoun
Keyword(s):  
Electronic Structure ◽  
Total Energy ◽  
Ab Initio ◽  
Structural Parameters ◽  
Ab Initio Study ◽  
Generalized Gradient ◽  
Generalized Gradient Approximation ◽  
Full Relaxation ◽  
Relaxation Procedure ◽  
Ternary Carbides

The Cr2AlC and V2AlC nanolayered ternary carbides are studied by performing APW-lo ab initio total energy calculations within the recent Wu-Cohen generalized gradient approximation GGA. Using full relaxation procedure of the volume and the atomic positions we obtained the structural parameters and electronic structure of the optimization hexagonal. Results were compared with the experimental ones. Interesting features are deduced. In fact, we have shown why these materials are conductors.

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