Density Functional Theory systematically underestimates electronic bandgaps due to derivative discontinuity errors
the verdict
SUPPORTED
the evidence backs this
confidence 89/100
Density Functional Theory systematically underestimates electronic bandgaps because standard exchange-correlation functionals lack the explicit derivative discontinuity required at integer particle numbers.
Evidence for · 2
Derivative discontinuity, bandgap and lowest unoccupied molecular orbital in density functional theory
2012 · cited by 174
Paper 0 establishes that the exact Kohn-Sham energy gap differs from the fundamental bandgap due to the functional derivative discontinuity of the exchange-correlation energy.
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More for · 1
Machine learning the derivative discontinuity of density-functional theory
2021 · cited by 1
Paper 3 explains that standard functionals fail to reproduce the fundamental derivative discontinuity at integer particle numbers, which is essential for accurate bandgap descriptions.