Journal ArticleDOI
Physical Content of the Exact Kohn-Sham Orbital Energies: Band Gaps and Derivative Discontinuities
John P. Perdew,Mel Levy +1 more
TLDR
In this paper, the Kohn-Sham density-functional theory was used to estimate the fundamental band gaps of semiconductors and insulators by about 40% due to derivative discontinuities of the exchange-correlation energy.Abstract:
The local-density approximation for the exchange-correlation potential understimates the fundamental band gaps of semiconductors and insulators by about 40%. It is argued here that underestimation of the gap width is also to be expected from the unknown exact potential of Kohn-Sham density-functional theory, because of derivative discontinuities of the exchange-correlation energy. The need for an energy-dependent potential in band theory is emphasized. The center of the gap, however, is predicted exactly by the Kohn-Sham band structure.read more
Citations
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Journal ArticleDOI
Influence of the exchange screening parameter on the performance of screened hybrid functionals.
TL;DR: This work reexamines the effect of the exchange screening parameter omega on the performance of the Heyd-Scuseria-Ernzerhof (HSE) screened hybrid functional and recommends a new version of HSE with the screened parameter omega=0.11 bohr(-1) for further use.
Journal ArticleDOI
The density functional formalism, its applications and prospects
Robert O. Jones,Olle Gunnarsson +1 more
TL;DR: In this paper, the authors survey the local density functional formalism and some of its applications and discuss the reasons for the successes and failures of the local-density approximation and some modifications.
Book
Electronic Structure: Basic Theory and Practical Methods
TL;DR: In this paper, the Kohn-Sham ansatz is used to solve the problem of determining the electronic structure of atoms, and the three basic methods for determining electronic structure are presented.
Journal ArticleDOI
First-principles calculations for defects and impurities: Applications to III-nitrides
TL;DR: In this paper, the authors describe the state-of-the-art computational methodology for calculating the structure and energetics of point defects and impurities in semiconductors and pay particular attention to computational aspects which are unique to defects or impurities, such as how to deal with charge states and how to describe and interpret transition levels.
Journal ArticleDOI
Density Functional Theory of Electronic Structure
TL;DR: In this article, the current status and trends of approximation methods (local density and generalized gradient approximations, hybrid methods) and the new light which density functional theory has been shedding on important concepts like electronegativity, hardness, and chemical reactivity index are discussed.