Transferable Total Energy Parametrization for Metals

1992 ◽  
Vol 291 ◽  
Author(s):  
M. Sigalas ◽  
D.A. Papaconstantopoulos
Keyword(s):  
Total Energy ◽  
Elastic Constants ◽  
First Principles ◽  
Tight Binding ◽  
Pair Potential ◽  
Full Potential ◽  
Potential Term ◽  
Order Polynomial ◽  
Total Energies ◽  
Good Agreement

ABSTRACTWe have investigated total energy expressions that consist of a term describing the eigenvalue sum and a pair potential term. Such expressions can be used to fit the results of first principles total energy calculations at given structures, and then obtain the total energy of another configuration of atoms avoiding the complexity of further ab initio calculations.In this work we present a method of fitting APW total energy results to a non-orthogonal tight-binding Hamiltonian from which the sum of the eigenvalues is derived and to a pair potential represented by a 5th order polynomial. We fit total energies for the fee and bec structures and we then obtain the elastic constants Cij in good agreement with both full potential LAPW calculations and experiment. We present results of this method for Ir.

First-Principles Calculations of the Elastic Properties of the Nickel-Based L12 Intermetallics

1995 ◽  
Vol 408 ◽  
Author(s):  
D. Iotova ◽  
N. Kioussis ◽  
S. P. Lim ◽  
S. Sun ◽  
R. Wu
Keyword(s):  
Electronic Structure ◽  
Total Energy ◽  
Ab Initio ◽  
Elastic Properties ◽  
Elastic Constants ◽  
First Principles ◽  
Anisotropy Factor ◽  
Full Potential ◽  
First Principles Calculations ◽  
Linear Muffin Tin Orbital

AbstractThe elastic constants of the L12-type ordered nickel-based intermetallics Ni3X (X = Mn, Al, Ga, Si, Ge), have been calculated by means of ab initio total-energy electronic structurecalculations based on the full-potential linear-muffin-tin-orbital (FLMTO) method. Theorigins in the electronic structure of the variation of the elastic constants, bulk and shearmoduli are investigated across the series, and the effects of the anisotropy of bonding chargedensity on the shear anisotropy factor and the degree of ductility is discussed.

Tight-Binding Hamiltonians for Carbon and Silicon

1997 ◽  
Vol 491 ◽  
Author(s):  
D. A. Papaconstantopoulos ◽  
M. J. Mehl ◽  
S. C. Erwin ◽  
M. R. Pederson
Keyword(s):  
Band Structure ◽  
Total Energy ◽  
Elastic Constants ◽  
First Principles ◽  
Equations Of State ◽  
Tight Binding ◽  
First Principles Calculations ◽  
Energy Bands ◽  
Tight Binding Method ◽  
Correct Energy

ABSTRACTWe demonstrate that our tight-binding method - which is based on fitting the energy bands and the total energy of first-principles calculations as a function of volume - can be easily extended to accurately describe carbon and silicon. We present equations of state that give the correct energy ordering between structures. We also show that quantities that were not fitted, such as elastic constants and the band structure of C60, can be reliably obtained from our scheme.

FIRST-PRINCIPLES HIGH-PRESSURE ELASTIC AND THERMODYNAMIC PROPERTIES OF TANTALUM

2011 ◽  
Vol 25 (10) ◽  
pp. 1393-1407 ◽  
Author(s):  
JING-HE WU ◽  
XIAN-LIN ZHAO ◽  
YOU-LIN SONG ◽  
GUO-DONG WU
Keyword(s):  
Thermodynamic Properties ◽  
Elastic Constants ◽  
First Principles ◽  
Equations Of State ◽  
Debye Model ◽  
Thermal Expansivity ◽  
Orbital Method ◽  
Full Potential ◽  
Body Centered Cubic ◽  
Theoretical Results

The all-electron full-potential linearized muffin-tin orbital method, by means of quasi-harmonic Debye model, is applied to investigate the elastic constant and thermodynamic properties of body-centered-cubic tantalum (bcc Ta). The calculated elastic constants of bcc Ta at 0 K is consistent with the previous experimental and theoretical results. Our calculations give the correct trends for the pressure dependence of elastic constants. By using the convenient quasi-harmonic Debye model, we refined the thermal equations of state. The thermal expansivity and some other thermal properties agree well with the previous experimental and theoretical results.

First-Principles Total Energy Study of NbCr2 + V Laves Phase Ternary System

1998 ◽  
Vol 552 ◽  
Author(s):  
Alim Ormeci ◽  
S. P. Chen ◽  
John M. Wills ◽  
R. C. Albers
Keyword(s):  
Ternary System ◽  
Total Energy ◽  
Density Of States ◽  
First Principles ◽  
Laves Phase ◽  
Full Potential ◽  
Self Consistent ◽  
Substitutional Defects ◽  
Cohesive Energies ◽  
Formation Energies

ABSTRACTThe C15 NbCr2 + V Laves phase ternary system is studied by using a first-principles, self-consistent, full-potential total energy method. Equilibrium lattice parameters, cohesive energies, density of states and formation energies of substitutional defects are calculated. Results of all these calculations show that in the C15 NbCr2 + V compounds, V atoms substitute Cr atoms only.

Composition and Strain Dependence of the Piezoelectric Coefficients in Semiconductor Alloys

2007 ◽  
Vol 1017 ◽  
Author(s):  
T. Hammerschmidt ◽  
M. A. Migliorato ◽  
D. Powell ◽  
A. G. Cullis ◽  
G. P. Srivastava
Keyword(s):  
First Principles ◽  
Density Functional ◽  
Piezoelectric Coefficient ◽  
Tight Binding ◽  
Tight Binding Model ◽  
Semiconductor Alloys ◽  
Binding Model ◽  
Functional Theory ◽  
Photo Current ◽  
Good Agreement

AbstractWe propose a tight-binding model for the polarization that considers direct and dipole contributions and employs microscopic quantities that can be calculated by first-principles methods, e.g. by employing Density Functional Theory (DFT). Applying our model to InxGa1-xAs alloys allows us to settle discrepancies between the values of e14 as obtained from experiments and from linear interpolations between the values of InAs and GaAs. Our calculated piezoelectric coefficient is in very good agreement with photo current measurements of InAs/GaAs(111) quantum well samples.

Automatic Determination of Tight-Binding Parameters in Bulk Systems

2013 ◽  
Vol 1523 ◽  
Author(s):  
Yasuaki Ohtani ◽  
Takeo Fujiwara ◽  
Shinya Nishino ◽  
Takashi Suzuki ◽  
Susumu Yamamoto ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
First Principles ◽  
Tight Binding ◽  
Crystalline Solid ◽  
Binding Parameters ◽  
Automatic Determination ◽  
Dynamics Calculation ◽  
Good Set ◽  
Good Agreement

ABSTRACTWe have studied a procedure to determine Tight-Binding (TB) parameters automatically, by which the band structure of the crystalline solid can be reproduced so as to be good agreement with that of first-principles molecular dynamics calculation. According to this procedure, we determine TB parameter sets for silicon and diamond accurately, and a fairly good set for their compound SiC.

First principles study of electronic and optical properties of InAs

Open Physics ◽  
2009 ◽  
Vol 7 (4) ◽  
Author(s):  
Zhenbao Feng ◽  
Haiquan Hu ◽  
Shouxin Cui ◽  
Wenjun Wang ◽  
Canyun Lu
Keyword(s):  
Optical Properties ◽  
First Principles ◽  
Optical Absorption Coefficient ◽  
Full Potential ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Augmented Plane Wave ◽  
Electronic And Optical Properties ◽  
Linearized Augmented Plane Wave ◽  
Good Agreement

AbstractThe electronic and optical properties of InAs in core-level spectra are calculated using the full-potential linearized augmented plane wave plus local orbitials (FP-LAPW +lo) method. The real and imaginary parts of the dielectric function ε(ω), the optical absorption coefficient I(ω), the reflectivity R(ω), the refractive index n(ω), and the extinction coefficient k(ω)are calculated. All these values are in good agreement with the experimental data. The effect of spin-orbit coupling on optical properties is also investigated and found to be quite small.

scholarly journals Deformation and Fracture Behavior of Tial

1990 ◽  
Vol 186 ◽  
Author(s):  
C. L. Fu ◽  
M. H. Yoo
Keyword(s):  
Flow Stress ◽  
Total Energy ◽  
Elastic Constants ◽  
First Principles ◽  
Fracture Behavior ◽  
Anomalous Temperature Dependence ◽  
Anomalous Temperature ◽  
Deformation And Fracture ◽  
Low Energies ◽  
Elastic Shear

AbstractFirst-principles total-energy calculations of the elastic constants, shear fault energies, and cleavage energies of TiAl are presented. We find a large elastic shear anisotropy along the [011] direction, and high APB energies due to the strong cohesion between Ti and Al layers. Shear faults of SISF, SESF, and twin boundary are predicted to be prevalent due to their low energies. The anomalous temperature dependence of flow stress is explained by the cross-slip pinning and fault dragging mechanisms. The intrinsic brittleness of TiAl is discussed in terms of the low mobility of 1/2[110] dislocations.

Structural Phase Stability of ThSb Under Pressure

1994 ◽  
Vol 364 ◽  
Author(s):  
B. Palanivel ◽  
G. Kalpana ◽  
M. Rajagopalan
Keyword(s):  
Phase Transition ◽  
High Pressure ◽  
Cell Volume ◽  
Structural Transition ◽  
Structural Phase ◽  
Tight Binding ◽  
Lmto Method ◽  
Cscl Structure ◽  
Total Energies ◽  
Good Agreement

AbstractThe electronic structure and high pressure structural phase transition in thorium antimonide have been investigated using the tight binding LMTO method. We have calculated the total energies by reducing the cell volume for NaCl as well as CsCl structures using TBLMTO method. The total energy calculations reveal that ThSb undergoes a structural transition from NaCl to CsCl structure at 78 kbar. The calculated value of equilibrium cell volume and the cell volume at which phase transition occurs are found to have a good agreement with the experimental results.

Sign in / Sign up

Export Citation Format

Share Document