Talk:Optimized effective potential method

I left the following feedback for the creator/future reviewers while reviewing this article:

1. This article badly needs more sources. For certain these exist, but need to be added.
2. There are many terms which are not defined -- you and I know what they are, but many readers won't.
3. You need to cite the instability, and mention why (if you can)
4. You omitted completely any of the reasons why OEP approaches could be useful. Perhaps mention the BJ and more recent mBJ, the Slater approximation then work up to the full form.

Ldm1954 (talk) 20:44, 25 March 2025 (UTC)[reply]

1. You are right about the sources. Albeit personally thinking, that the Kümmel, KLI, Görling-(Levy) papers are some of the best and clearest papers regarding OEP, i will look up for other references. Especially there was a perfectly written 60-pages long manuscript about OEP, i hope i can still find. I will add the smiga paper, where they did OEP for the non-interacting KS kinetic energy, highlighting you can in principle take any orbital-dependent functional.

2. If i am not mistaken, the terms not defined are the electronic coordinates r,r', the dagger symbol, the 4-index integral, the KS potential. I will add those.

3. Ok. I will cite the instability and outline reasons.

4. I did not omit completely any reasons why OEP approaches could be useful, on the contrary c.f. I wrote: "is a method to determine the potentials as functional derivatives of the corresponding KS orbital-dependent energy density functionals" (That is basically the whole point of OEP in the lead section already). Or much more in detail in the background section "The problem is that, although the xc energy is in principle (due to the Hohenberg-Kohn (HK) theorem) a functional of the density, its explicit dependence on the density is unknown (only known in the simple Local density approximation (LDA) case), only its implicit dependence through the KS orbitals. That motivates the use of the chain rule [...] So one needs to invoke the chain rule once more, now with respect to the Kohn-Sham (KS) potential"

5. In one clarification needed you said "Surely as defined only the occupied orbitals?" No. I purposefully wrote both. If OEP is done for the exchange energy E_x you are right! But if OEP is done in general for the exchange-correlation energy E_xc then its both, since the correlation energy is highly dependent on unoccupied KS orbitals and eigenvalues (c.f. 5th rung of Jacob's Ladder from Perdew) The Quantum Chemist (talk) 23:04, 1 April 2025 (UTC)[reply]

You still need to do something about the lead. It should have a few sentences to a first paragraph that is understandable by a 1st year physics undergrad. After that you can go more complex. Ldm1954 (talk) 16:20, 3 April 2025 (UTC)[reply]

to (4.) I guess with (m)BJ you mean the (modified) Becke-Johnson exchange potential. I have read a lot about OEP, the connection to Green's function theory, the Krieger, Li, Iafrate (KLI) approximation and so on ..., but in all honesty and modesty I must admit to not having heard BJ before you mentioned it despite being cited over 1,7k times. That is astounding. Seems like everybody is a life-long learner even in their own field :). Regarding the circumstance I outlined above, I don't feel qualified enough adding (m)BJ to the OEP article. Would you like to take over this task @Ldm1954? The Quantum Chemist (talk) 00:11, 2 April 2025 (UTC)[reply]