UT theoretical chemistry code forum

Dear all,
I find a strong p-d hybridization from DOS, can I absolutely say that the metal-oxygen bond must be covalent bond?
But I found from ELF, that the oxide display a ionic character.
I donot known where I made a mistake,
Thanks.

[quote="graeme"]Assuming that the core levels are the same in the two systems then (Ef1-Ep1)-(Ef2-Ep2) = delta Ef will be the difference in the Fermi level.[/quote]
Thanks, Prof. Graeme. Futhermore, I compute the core level under different pressure (not too high) with different crystal structrues ...

[quote="graeme"]In my experience it is pretty clear when the core states are aligned when comparing the DOS of two structures. While there may be small shifts in the core levels, it is unlikely for there to be a systematic shift in all of the core levels that you can calculate. Anyway, for practical ...

[quote="graeme"]For bulk calculations, the energy levels of low-lying (core) electronic states works pretty well (note that you may have to include s or p electrons as valance to do this well).[/quote]
Thanks. Dear Prof. Graeme, I want to knwon how to detaily do this alignment in VASP. Is it ture ...

Dear all,
I read the paper (PHYSICAL REVIEW B 88, 054111 (2013)
Strain-controlled oxygen vacancy formation and ordering in CaMnO3)
which mainly discuss the DOS change with and whithout oxygen vacancies under starin.
The paper said that "The energy scales of the stoichiometric DOS have been aligned ...

[quote="graeme"]You can set ISIF=3 to relax the stress.[/quote]
Thanks, Dr. Graeme, I often use ISIF=3 to relax the stress, but the stress in x y z directions are all less than 1kBa,
So I am very want to know how do they make stress less than 0.1kBa?

Dear all,
I am a beginner of VASP, recently I often see the authors say they make stresses in a relaxed structure less than 0.1 kBa, but I found my calculations often have strss less than 1kBa in x y z directions, so my question is how can make stresses in a relaxed structure less than 0.1 kBa ...