First-Principles Calculation of Force Constants and Full Phonon Dispersions

1992 ◽  
Vol 291 ◽  
Author(s):  
Siqing Wei ◽  
M. Y. Chou
Keyword(s):  
First Principles ◽  
Phonon Dispersion ◽  
Local Density ◽  
Real Space ◽  
Force Constants ◽  
First Principles Calculation ◽  
Dynamical Matrix ◽  
Phonon Dispersion Curves ◽  
Super Cell ◽  
Silicon And Germanium

ABSTRACTWe calculated the real-space force constants and full phonon dispersion curves for elemental semiconductors (silicon and germanium) under the local-density approximation with the Hellmann-Feynman forces. The force constants are obtained through super- cell calculations for planar displacements in three different symmetry directions. From these real-space force constants the dynamical matrix for an arbitrary wave vector in the Brillouin zone can be constructed. The procedure is simple in concept and requires no complicated computer programing. It is also possible in principle to handle the anharmonic effects.

A Method for the Determination of Real-Space Interatomic Force-Constants.

1992 ◽  
Vol 291 ◽  
Author(s):  
Andrew A. Quong ◽  
Amy Y. Liu ◽  
Barry M. Klein
Keyword(s):  
Phonon Dispersion ◽  
Linear Response Theory ◽  
Real Space ◽  
Force Constants ◽  
The Self ◽  
Electron Interaction ◽  
Dynamical Matrix ◽  
Interatomic Force ◽  
Self Consistent

ABSTRACTWe present a method for the self-consistent determination of inter-atomic force-constants. Using non-local ab-initio pseudopotentials to represent the ion-electron interaction and linear response theory to calculate the self-consistent change in the electron density, we are able to calculate the dynamical matrices at arbitrary points in the Brillouin zone. Diagonalization of the dynamical matrix yields phonon eigenvectors and eigenvalues, and fourier inversion yields the real-space interatomic force-constants. We present numerical results for the phonon-dispersion of a variety of metals.

Phonon renormalization of the electronic effective mass

1969 ◽  
Vol 47 (10) ◽  
pp. 1107-1116 ◽  
Author(s):  
J. P. Carbotte ◽  
R. C. Dynes ◽  
P. N. Trofimenkoff
Keyword(s):  
Effective Mass ◽  
Phonon Dispersion ◽  
Inelastic Neutron Scattering ◽  
Inelastic Neutron ◽  
Force Constants ◽  
Coupling Constant ◽  
Phonon Dispersion Curves ◽  
Electron Phonon Interaction ◽  
Phonon Renormalization ◽  
Pseudo Potential

We have made detailed first principle calculations of the phonon contribution to the renormalization of the electronic effective mass of a number of simple metals and alloys. The phonon frequencies and polarization vectors are generated from the interatomic force constants for the material. The force constants are taken from a Born – von Kármán analysis of the experimental phonon dispersion curves determined by inelastic neutron scattering. The electron–phonon interaction is treated using pseudo-potential theory which relates the coupling constant to the electron–ion form factor. For a spherical Fermi surface it is then possible to evaluate numerically the expression for the effective mass with no further approximations. We compare the results obtained with previous work when available and with experiment otherwise.

scholarly journals Structural and Electronic Properties of Orthorhombic Phase Bi2Se3 Based On First-Principles Study

2019 ◽  
Vol 16 (2) ◽  
pp. 77 ◽  
Author(s):  
Muhammad Zamir Mohyedin ◽  
Afiq Radzwan ◽  
Mohammad Fariz Mohamad Taib ◽  
Rosnah Zakaria ◽  
Nor Kartini Jaafar ◽  
...  
Keyword(s):  
Electronic Properties ◽  
First Principles ◽  
Density Functional ◽  
Local Density ◽  
Computer Code ◽  
First Principles Calculation ◽  
Generalized Gradient ◽  
Exchange Correlation ◽  
Percentage Difference ◽  
Structural And Electronic Properties

Bi2Se3 is one of the promising materials in thermoelectric devices and very useful out of environmental concern due to its efficiency to perform at room temperature. Based on the first-principles calculation of density functional theory (DFT) by using CASTEP computer code, structural and electronic properties of Bi2Se3 were investigated. The calculation is conducted within the exchange-correlation of local density approximation (LDA) and generalized gradient approximation within the revision of Perdew-Burke-Ernzerhof (GGA-PBE) functional. It was found that the results are consistent with previous works of theoretical study with small percentage difference. LDA exchange-correlation functional method is more accurate and have a better agreement than GGA-PBE to describe the structural properties of Bi2Se3 which consist of lattice parameters. LDA functional also shown more accurate electronic structure of Bi2Se3 that consist of band structure and density of states (DOS) which consistent with most previous theoretical works with small percentage difference. This study proves the reliability of CASTEP computer code and show LDA exchange-correlation functional is more accurate in describing the nature of Bi2Se3 compared to the other functionals.

AB INITIO STUDY OF PHONON DISPERSION AND ELASTIC PROPERTIES OF L12 INTERMETALLICS Ti3Al AND Y3Al

2013 ◽  
Vol 27 (30) ◽  
pp. 1350224 ◽  
Author(s):  
N. ARIKAN ◽  
M. ERSEN ◽  
H. Y. OCAK ◽  
A. İYIGÖR ◽  
A. CANDAN ◽  
...  
Keyword(s):  
First Principles ◽  
Density Functional ◽  
Phonon Dispersion ◽  
High Symmetry ◽  
Generalized Gradient ◽  
Pressure Derivative ◽  
Phonon Dispersion Curves ◽  
Lattice Constants ◽  
Density Functional Perturbation Theory ◽  
Phonon Properties

In this paper, the structural, elastic and phonon properties of Ti 3 Al and Y 3 Al in L1 2( Cu 3 Al ) phase are studied by performing first-principles calculations within the generalized gradient approximation. The calculated lattice constants, static bulk moduli, first-order pressure derivative of bulk moduli and elastic constants for both compounds are reported. The phonon dispersion curves along several high-symmetry lines at the Brillouin zone, together with the corresponding phonon density of states, are determined using the first-principles linear-response approach of the density functional perturbation theory. Temperature variations of specific heat in the range of 0–500 K are obtained using the quasi-harmonic model.

Pressure effects on mechanical and electronic properties of metallic C14 by first-principles calculation

2019 ◽  
Vol 33 (18) ◽  
pp. 1950193
Author(s):  
Yingjiao Zhou ◽  
Qun Wei ◽  
Bing Wei ◽  
Ruike Yang ◽  
Ke Cheng ◽  
...  
Keyword(s):  
High Pressure ◽  
Thermodynamic Properties ◽  
First Principles ◽  
Pressure Range ◽  
Phonon Dispersion ◽  
Elastic Anisotropy ◽  
Acoustic Velocity ◽  
Pressure Effects ◽  
First Principles Calculation ◽  
First Principles Calculations

The elastic constants and phonon dispersion of metallic C[Formula: see text] are calculated by first-principles calculations. The results show that the metallic C[Formula: see text] is mechanically and dynamically stable under high pressure. The variations of G/B ratio, Poisson’s ratio, elastic anisotropy, acoustic velocity and Debye temperature at the pressure range from 0 GPa to 100 GPa are analyzed. The results reveal that by adjusting the pressures the elastic anisotropy and thermodynamic properties could be improved for better applicability.

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