Local density approximation versus generalized gradient approximation:

We systematically performed first-principles investigations of the structural properties, electron energy band, and densities of states (DOS) for ThO2. All calculations were carried out using the local density approximation (LDA), generalized gradient approximation (GGA), LDA+U, and GGA+U approaches. We also compared our findings with experimental data and other calculations. The lattice parameter obtained using the GGA+U agrees well with the experimental value.

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Long-range and short-range Coulomb correlation effects as simulated by Hartree-Fock, local density approximation, and generalized gradient approximation exchange functionals

Theoretical Chemistry Accounts ◽

10.1007/s00214-002-0398-y ◽

2003 ◽

Vol 109 (1) ◽

pp. 22-35 ◽

Cited By ~ 57

Author(s):

Victor Polo ◽

Jürgen Gräfenstein ◽

Elfi Kraka ◽

Dieter Cremer

Keyword(s):

Long Range ◽

Local Density Approximation ◽

Short Range ◽

Local Density ◽

Density Approximation ◽

Coulomb Correlation ◽

Correlation Effects ◽

Generalized Gradient ◽

Hartree Fock ◽

Generalized Gradient Approximation

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A Comparative Study of the Influence of the Local Density Approximation and the Generalized Gradient Approximation on the Calculated Properties of the III-Nitride (110) Surfaces

MRS Proceedings ◽

10.1557/proc-639-g11.46 ◽

2000 ◽

Vol 639 ◽

Author(s):

H. W. Leite Alves ◽

J. L. A. Alves ◽

R. A. Nogueira ◽

J. R. Leite

Keyword(s):

Local Density Approximation ◽

Density Functional ◽

Local Density ◽

Structural Parameters ◽

Full Potential ◽

Density Approximation ◽

Generalized Gradient ◽

Generalized Gradient Approximation ◽

The Density Functional Theory ◽

Supercell Model

ABSTRACTWe present a systematic theoretical study of several III-nitride (110) surfaces based on accurate parameter-free, self-consistent total energy and force calculations using the density functional theory, the local density approximation (LDA), as parametrized by Perdew and Zunger, and the generalized gradient approximation (GGA), as proposed by Perdew, Burke, and Ernzerhof, for the exchange-correlation term; we use the Full Potential Linear Augmented Plane Wave (FPLAPW) approach (WIEN-97 code) associated with the slab supercell model to simulate the (110) surface. We studied BN, AlN, GaN, InN and compared the theoretical results as related to the use of the LDA and the GGA. We conclude that although the results for both approximations are similar, differences in structural parameters may be as large as 10%.

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FIRST-PRINCIPLES STUDY OF GAMMA-Si3N4 WITH GENERALIZED GRADIENT APPROXIMATION AND LOCAL DENSITY APPROXIMATION

International Journal of Modern Physics B ◽

10.1142/s0217979208039368 ◽

2008 ◽

Vol 22 (13) ◽

pp. 2157-2167 ◽

Cited By ~ 9

Author(s):

YINGCHUN DING ◽

HAIPING ZHOU ◽

MING XU ◽

YIBING SHEN ◽

QINGYUN CHEN ◽

...

Keyword(s):

Local Density Approximation ◽

Local Density ◽

Potential Method ◽

Comparative Investigation ◽

Density Approximation ◽

Generalized Gradient ◽

Generalized Gradient Approximation ◽

Structures And Properties ◽

Optical And Mechanical Properties ◽

Pseudo Potential

The electronic structure, and optical and mechanical properties of gamma- Si 3 N 4 are calculated by means of the plane-wave pseudo-potential method (PWP) with generalized gradient approximation (GGA) and local density approximation (LDA). The calculated values are in good agreement with experimental results. A comparative investigation reveals that the band gap calculated by GGA agrees better with the experimental value than by the other methods, while the calculated bulk modulus by LDA is comparable with that by the method of orthogonalized linear combinations of atomic orbitals (OLCAO). Our results indicate that a satisfactory calculation of the structures and properties of gamma- Si 3 N 4 could be achieved by combining GGA and LDA methods.

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