scholarly journals Band gaps and structural properties of graphene halides and their derivates: A hybrid functional study with localized orbital basis sets

2012 ◽  
Vol 137 (3) ◽  
pp. 034709 ◽  
Author(s):  
František Karlický ◽  
Radek Zbořil ◽  
Michal Otyepka
Keyword(s):  
Structural Properties ◽  
Band Gaps ◽  
Basis Sets ◽  
Functional Study ◽  
Hybrid Functional ◽  
Orbital Basis ◽  
Localized Orbital

scholarly journals Improved Band Gaps and Structural Properties from Wannier-Fermi-Lowdin Self-Interaction Corrections for Periodic Systems

2020 ◽  
Author(s):  
Ravindra Shinde ◽  
Sharma Yamijala ◽  
Bryan Wong
Keyword(s):  
Structural Properties ◽  
Wide Bandgap ◽  
Band Gaps ◽  
Structure Theory ◽  
Periodic Systems ◽  
Molecular Solids ◽  
Hybrid Functional ◽  
Variational Minimization ◽  
Wide Bandgap Materials ◽  
New Formulation

The accurate prediction of band gaps and structural properties in periodic systems continues to be one of the central goals of electronic structure theory. However, band gaps obtained from popular exchange-correlation functionals (such as LDA and PBE) are severely underestimated partly due to the spurious self-interaction error (SIE) inherent to these functionals. In this work, we present a new formulation and implementation of Wannier function-derived Fermi-Lowdin (WFL) orbitals for correcting the SIE in periodic systems. Since our approach utilizes a variational minimization of the self-interaction energy with respect to the Wannier charge centers, it is computationally more efficient than the HSE hybrid functional and other self-interaction corrections that require a large number of transformation matrix elements. Calculations on several (17 in total) prototypical molecular solids, semiconductors, and wide-bandgap materials show that our WFL self-interaction correction approach gives better band gaps and bulk moduli compared to semilocal functionals, largely due to the partial removal of self-interaction errors.

scholarly journals Improved Band Gaps and Structural Properties from Wannier-Fermi-Lowdin Self-Interaction Corrections for Periodic Systems

2020 ◽  
Author(s):  
Ravindra Shinde ◽  
Sharma Yamijala ◽  
Bryan Wong
Keyword(s):  
Structural Properties ◽  
Wide Bandgap ◽  
Band Gaps ◽  
Structure Theory ◽  
Periodic Systems ◽  
Molecular Solids ◽  
Hybrid Functional ◽  
Variational Minimization ◽  
Wide Bandgap Materials ◽  
New Formulation

The accurate prediction of band gaps and structural properties in periodic systems continues to be one of the central goals of electronic structure theory. However, band gaps obtained from popular exchange-correlation functionals (such as LDA and PBE) are severely underestimated partly due to the spurious self-interaction error (SIE) inherent to these functionals. In this work, we present a new formulation and implementation of Wannier function-derived Fermi-Lowdin (WFL) orbitals for correcting the SIE in periodic systems. Since our approach utilizes a variational minimization of the self-interaction energy with respect to the Wannier charge centers, it is computationally more efficient than the HSE hybrid functional and other self-interaction corrections that require a large number of transformation matrix elements. Calculations on several (17 in total) prototypical molecular solids, semiconductors, and wide-bandgap materials show that our WFL self-interaction correction approach gives better band gaps and bulk moduli compared to semilocal functionals, largely due to the partial removal of self-interaction errors.

Concentration of point defects in wurtzite AlN: A hybrid functional study

2012 ◽  
Vol 98 (3) ◽  
pp. 36003 ◽  
Author(s):  
Leonardo Silvestri ◽  
Kerry Dunn ◽  
Steven Prawer ◽  
François Ladouceur
Keyword(s):  
Point Defects ◽  
Functional Study ◽  
Hybrid Functional

A comparative study on the LDA + U and hybrid functional methods on the description of the electronic structure of YTiO3 under high pressure

2009 ◽  
Vol 87 (10) ◽  
pp. 1374-1382 ◽  
Author(s):  
Z. Song ◽  
J. J. Yang ◽  
J. S. Tse
Keyword(s):  
Electronic Structures ◽  
Local Density ◽  
Band Gaps ◽  
Density Approximation ◽  
Hybrid Functional ◽  
Functional Methods ◽  
Mixing Parameters ◽  
Hubbard U ◽  
Hubbard Parameter ◽  
Pressure Analysis

The electronic structures of YTiO3 under pressure have been studied with LDA + U (local density approximation + Hubbard parameter) and hybrid functional methods. From matching the experimental band gaps, the Hubbard U and hybrid functional mixing parameters were determined. It is found that both parameters vary with the pressure. Analysis of the electronic structures indicates that the description of the chemical bonding is also dependent on the method of choice.

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