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Total vdW correction during optB88 functional
Posted: Mon May 04, 2026 8:56 am
by naveen_sharma
Hello community,
I used optB88 functional for structure relaxation of one of heterostructure system. After my calculation is completed, I am getting a positive Total vdW correction in eV of 7.2178333. It doesn't make sense to me. My doubt is - is it printing only the E_c^nl term here or the complete difference??
Kindly answer and thanks for your time.
Re: Total vdW correction during optB88 functional
Posted: Mon May 04, 2026 3:01 pm
by henrique_miranda
The positive value seems indeed correct.
What is shown there is an additional E_cnl contribution that gets added to the total energy.
You can check that it is so by setting LUSE_VDW to true or false and comparting the total energies that you get in the end.
They should roughly match + a small difference because these non-local vdw XC change the potential too.