7
$\begingroup$

I am wondering whether or not self-interaction error and integer-discontinuity in Kohn-Sham density functionals, are related to each other?

$\endgroup$
4
$\begingroup$

Yes and no.

The exact functional should have a piecewise linear behavior in the number of electrons Phys. Rev. Lett. 49, 1691 (1982), but this is not true for common density functional approximations, and self-interaction errors do affect behavior at fractional electron numbers.

Now, if you apply the Perdew-Zunger self-interaction correction, then not only do you mitigate the one-electron self-interaction error (N.B. the correction is often problematic, see Adv. At., Mol., Opt. Phys. 64, 1 (2015) and J. Chem. Theory Comput. 12, 3195 (2016)) but also introduce step-wise behavior in the functional due to the added term; orbital energies in PZ-SIC are often better than in Kohn-Sham DFT. There's also been a lot of work on the so-called Koopmans' compliant functionals by Marzari et al.

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.