scholarly journals Ab Initio Calculation of Tight-Binding Parameters

1997 ◽  
Vol 491 ◽  
Author(s):  
A. K. Mcmahan ◽  
J. E. Klepeis
Keyword(s):  
Ab Initio ◽  
Density Functional ◽  
Local Density ◽  
Tight Binding ◽  
Matrix Elements ◽  
Binding Parameters ◽  
Minimal Basis ◽  
The Common ◽  
Local Density Functional ◽  
Overlap Matrix

ABSTRACTWe calculate ab initio values of tight-binding parameters for the /-electron metal Ce and various phases of Si, from local-density functional one-electron Hamiltonian and overlap matrix elements. Our approach allows us to unambiguously test the validity of the common minimal basis and two-center approximations as well as to determine the degree of transferability of both nonorthogonal and orthogonal hopping parameters in the cases considered.

GaAs Total Energy Tight Binding Hamiltonians for use in Molecular Dynamics

1990 ◽  
Vol 193 ◽  
Author(s):  
Jeremy Broughton ◽  
Mark Pederson ◽  
Dimitrios Papaconstantopoulos ◽  
David Singh
Keyword(s):  
Density Functional ◽  
Local Density ◽  
Tight Binding ◽  
Large Data ◽  
Matrix Elements ◽  
Energy Matrix ◽  
Self Consistent ◽  
Total Energies ◽  
Local Density Functional ◽  
Semi Empirical

ABSTRACTA self-consistent non-orthogonal semi-empirical tight binding Hamiltonian is proposed for GaAs, or any sp system, which is simple, reliable, transferable, accurate and fast to evaluate. Matrix elements are functions of charges, distances between atoms and simple cosines of angles between s and p-electron densities and interatomic vectors which maintain the simplicity of Slater-Koster parameterizations. The tight binding scheme is fit against a large data base of local density functional derived total energies for systems of differing coordination and geometry. The Hamiltonian fulfills the correct Virial constraint, invokes the physically correct relationship between overlap and kinetic energy matrix elements and defines charges via Mulliken or Löwdin schemes. Such Hamiltonians will allow the reliable simulation of statistical mechanically interesting systems of order hundred or more atoms over physically useful periods of time of order tens to hundreds of thousands of time steps within not unreasonable supercomputer budgets.

Hydrogen Passivated Carbon Acceptors in GaAs and AlAs: no Evidence for Carbon Donors

1993 ◽  
Vol 325 ◽  
Author(s):  
B. R. Davidson ◽  
R. C. Newman ◽  
R. E. Pritchard ◽  
T. J. Bullough ◽  
T. B. Joyce ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Ab Initio ◽  
Infrared Absorption ◽  
Density Functional ◽  
Local Density ◽  
Absorption Lines ◽  
Functional Theory ◽  
Local Density Functional Theory ◽  
Local Density Functional

AbstractGaAs and AlAs layers grown by CBE and doped with either 12C or 13C have been passivated with hydrogen or deuterium. Infrared absorption lines due to hydrogen stretch modes, symmetric A1 modes and “carbon-like” E modes of H-CAs and D-CAs pairs have been assigned for both isotopes in both hosts. Comparisons have been made with new ab initio local density functional theory and simple harmonic models. Anticrossing behaviour is found for the two types of coupled E modes in the two hosts. The dynamics of the H-CAs centre are very similar in GaAs and AlAs.

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