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Author Topic: Underestimation of bandgap  (Read 2972 times)

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Offline abhishek77492652

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Underestimation of bandgap
« on: September 27, 2017, 19:37 »
Why DFT-GGA and DFT-LDA underestimate the bandgap  of  non-metals ?
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Offline Daniele Stradi

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Re: Underestimation of bandgap
« Reply #1 on: September 28, 2017, 09:16 »
Because of the so-called self-interaction error due to the use of approximate exchange-correlation functionals. See e.g.:

J. P. Perdew and Alex Zunger
Self-interaction correction to density-functional approximations for many-electron systems
Phys. Rev. B 23, 5048
https://journals.aps.org/prb/abstract/10.1103/PhysRevB.23.5048
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